Have you ever noticed that the notions of "male/female leads" and the bullshit term "deuteragonist" are mainly used to undermine a female protagonist's importance? These are fandom terms that are used to complain that a male character is not important enough or to elevate his status as a main supporting character (oftentimes the love interest when it comes to "leads") to the same level as the protagonist. She, who is already ignored by the fans, never gets to be the sole main character of her tale. She must always share her place with a much more appealing man. No matter how obvious it is that this is her story, if a man has any amount of importance in it then he must be equally as important as her.
Take Miraculous for example: this show, since its conception, has always been a single protagonist story. Marinette, and her famous secret identity Ladybug, is our entry into this world. We see the story from her perspective. The structure of every episode, as per the main writer Astruc stated, revolved around her making a mistake that must be fixed. The theme song is a cliché retelling of who she is and the premise of the show. Yet, countless fans are upset about it. Indeed, Marinette has a crush on the dreamy Adrien, who conveniently also has a secret identity, Cat Noir, and is Ladybug's superhero partner. Adrien is unlucky as, alas, his father happens to be the antagonist of the show—unbeknown to him, of course. It's fair to say that Adrien is an important character. In fact, he is likely the most important side character of the story. This is not uncommon for magical girls narratives. Sailor Moon, one of Miraculous' inspirations, uses a similar formula: the eponymous Sailor Moon's love interest is present in both her civilian and magical girl life. His goal is to get the same special object as her, for originally unknown reasons, and the show—alongside its manga iteration—does spend some time fleshing them out. When he is not busy helping Sailor Moon out, he wakes up from strange dreams about the equally mysterious princess that Sailor Moon is also searching for. And when he is not busy with all of that, he is the guy teasing Sailor Moon's civilian identity. However, one cannot deny that Sailor Moon is the protagonist of her story and that her love interest is just that, no matter how involved he is in the story. A common defense for Adrien's Schrodinger's protagonism is that his name is in the subtitle. That's right, the full title is Miraculous: The Tales of Ladybug and Cat Noir. To note that it is far more commonly reduced to Miraculous Ladybug and, especially recently, Miraculous. The importance of these shorter titles tells of which character is the most important one. We must also note that it is not uncommon for titles to name more than the main character. There are examples of this across mediums and genres. To stay in the animated realm: Winx, Pretty Cure, or even animes like Inazuma Eleven include the protagonist's wider friendgroup in their titles. It does not take away Bloom, the main Precure of the new season (usually color-coded with pink), or Mamoru's protagonism. Titles do not always indicate who is the main character. Especially not when they are based on one or multiple characters. Heathers being named after a group of three girls all named Heather does not mean that its protagonist is not Veronica. It does not mean that these "Heathers" are the antagonists either. It hints at their importance in the narrative rather than state their status. That is what titles are meant to convey. An important theme, character, or idea in the story. Miraculous does so by including its main supporting character. After all, Adrien/Cat Noir is crucial to the plot. Furthermore, it may strike the audience as strange to exclude the other superhero from the title. Miraculous nonetheless constantly establishes that Marinette is the sole protagonist through and through. The way the writing may underutilize Adrien is not linked to him supposedly being another protagonist. In fact, his status as a main character is doubtful as Adrien does not have much of an arc but, on the other hand, he is the beloved archetype and impacted by the plot. Ultimately, it does not really matter as "main character" does not mean "protagonist". The former includes different archetypes such as the antagonist and, well, the beloved. It's alright if that is what Adrien is.
The issue is that the fandom demands that Adrien be more than he is and has always been. To them, his status is inherently higher for no reason other than existing. This type of belief is less common if the genders were reversed. There is, from my observation, more acceptance of female characters as a supporting cast than the reverse. It will shock no one when I say that fandoms are heavily male-focused. This is a symptom of many, many issues but the fact remains that male characters will inevitably receive more attention than female ones most of the time. This, I believe, manifests in how fans perceive a male character's narrative place. The gender segregation of "leads" does not appear nearly as much when the protagonist is a man. The love interest is accepted as a love interest then. The use of these terms has its own set of issues: what about same-gender romances? How often is "non-binary lead" used? Should we have names only for heterosexual romances? What does the love interest lead? They are oftentimes not a protagonist. They exist as a goal. Perhaps it is a repercussion of theater vocabulary (namely "leading man" and "leading woman") but what is the point in adopting it for fictional characters?
Another egregious but lesser example would be Alien Stage's Till. Alien Stage has been stated to be the story of female protagonist Mizi. It is her journey that we follow despite the supporting cast having a strong narrative presence. Their own stories serve to explain Mizi's descent into madness. This multimedia's biggest twist centers around Mizi. She may have been presented as a rather simple character but this twist, heavily influenced by the plight of the rest of the cast, reveals a complexity that the audience should have but did not expect. Despite her original presentation, Mizi is heavily featured across the video part of the project, starring in all but maybe one video. The comics and illustration will venture towards other characters not unlike a dedicated episode or chapter. Once again, all of this builds up Mizi's tragedy and the reveal that she is like them. Alien Stage mainly features women. Its cast has an equal ratio but it is mainly through the female characters that the most changes are done. Mizi and her lover Sua are what introduce the audience to the main themes, alongside a general introduction, and the rebel Hyuna introduces us to a new vision of the world. Mizi and Sua let us into oppression they face and its end result while Hyuna shares the freedom they should all have, how some are fighting for a better world. The male characters are all a part of the oppression side of the story. They have their own plotlines, their own raison d'être, but they don't introduce anything new to the audience. Their tragedies follow Mizi and Sua's—who themselves were indeed the template for every other character. This brings us to Till. Till is the third character officially introduced. His episode is spent thinking about Mizi. Though he still has his own dilemmas outside of her, Mizi is crucial to his character—something that is not reciprocated. Mizi herself revolves around Sua, with Till taking on the role of an acquaintance. In her storyline, Till is only relevant around the end when he is the last of her friends to die to oppression. He is not the trigger that leads her to commit her worst sin (that would be Hyuna) but he is the key to snapping her out of her trauma-induced nihilism. Alien Stage ends with Till as a symbol of a possible better future. It is more the ideas associated with him than him as a character that seems to lead this decision. Till himself does not do much in the story, does not appear much outside of his and his love interest's dedicated time. Moreover, Till is one of the few characters whose point of view is barely explored until the end—grouped with Mizi and Luka who are left alone for narrative reasons. We get a few glimpses of Till's point of view around the end as he becomes a sort of "in" point of view to contrast with the new and more objective, point of view of Isaac, an outsider to this story. Despite all of this, there is a subsection of fans claiming that Till is a protagonist. Because he survived, he cannot be a supporting character. Alien Stage does blur the line between a one protagonist story and an ensemble cast but this logic excludes the four other important characters of the story. If one would argue that it is not a single protagonist story then they must argue that it is an ensemble cast narrative.
The Alien Stage fandom is very male-focused despite the central role women play. It is the plotline between Ivan and Till that attracted a lot of attention so, naturally, they are favored by many of these people. Their merchandise is the one that sells the best. What they appear in gathers the most attention. Strangely enough, the third male character Luka, who revolves solely around Hyuna, is also more popular than his female counterpart. Despite having, for good reason, the least amount of dedicated time, he manages to rise above his love interest that is crucial to the plot, appears more, and is thoroughly explored. To call Hyuna his love interest would be a disservice. He is her (complicated) love interest. Hyuna has been called by the creators, Vivinos and QMeng, a true protagonist. They were referring to her virtues compared to Mizi's, how Hyuna represents Good and virtue, how her selflessness contrasts Mizi's human selfishness, but it is a testament to how important she is. Mizi is the protagonist but no hero nor villain until she falls from grace. Hyuna would have been otherwise the very stereotypical protagonist of a story about rebellion. Therefore, it is rather disappointing that these two men, Till and Luka, who orbit the two major female characters are favored by the fans. (Ivan is an exception. His character centers around Till with only weaker links to Sua and Mizi. By refusing to have their gay character heavily tied to women and their lesbian characters to men, Vivinos and QMeng implicitly reject any notion of heteronormative storytelling, same-gender relationships can stand on their own without relying on the other gender. This doesn't apply to a character like Till whose bisexuality is heavily implied and his original attraction to a woman is crucial to his arc.)
The men are favored and so when Till is being elevated to Mizi's level, it cannot reasonably be chalked up to mere favoritism. It is a female protagonist's importance being reduced because of bias towards male characters and the need to have these two genders be as important as one another when the story follows a woman. This is not the same as fans elevating female characters to match a male protagonist unless it is for a specific type of narrative that is only applicable to men and is a type of representation to them (ie: a gay story). Women, fictional or not, are not treated the same way as men and this phenomenon is a symptom of patriarchy and misogyny. Bringing men up and taking away from women when talking about women is not equality. It cannot be compared to attempts to bring attention to female characters.
As a side note because it is a hot topic at the moment:The Amazing Digital Circus could be brought up in this discussion but the writing is too unstructured for me to properly analyze it. Jax's introduction is not clear enough to be able to tell if it was a subversion or purpose or a retcon. There is also the fact that Jax is an antagonist, therefore a main character, so exploring that type of character is unsurprising yet the degree to which it is done and how it is executed turns it into the story being taken over by another character. It is made more complex by the underlying transfeminine storyline that is not something I am educated on enough to begin to tackle. How it was executed certainly does not help as it requires knowledge I do not have and areas I have not studied. Jax being elevated by fans to a protagonist does ring as wrong but I do not think it should be attributed to the fans but to the writing being unclear on Jax's narrative role. Jax is important like Caine is important. They are both antagonists so the focus on them is natural. It is also done by the show itself rather than, like the previous examples, done by the fans against what the show has established. The Amazing Digital Circus does not fit what this about.