i genuinely think that the "unrelatable main character" brand of acolyte haters (as well as seemingly good-faith critics) were telling on themselves so much. Osha's character and story has so much for most viewers to see themselves in, if they are at all willing to try to relate to a woman of color. more than most star wars protagonists if we're being honest
worshiping/admiring the jedi as a kid and wanting to be one? pretty common for people who grow up watching star wars, and yeah, multiple star wars characters have that trait/backstory to some extent. how about realizing that you simply cannot be one? or that you love them but their lifestyle would actually not be for you at all? or that, upon further reflection, you don't agree with them on everything? a wide spectrum of reactions to this faction, all common in the viewership and all exhibited by our protagonist.
related to that, feeling you aren't good enough, warranted or not? that you disappointed your mentors and the dreams of your younger self? several star wars protagonists struggle with feelings of inadequacy, but they are rarely as persistent and central to their story.
clashing with your parents/family about what's best for you? a common situation one might like to process through media, and not particularly present in main star wars characters (examples i can think of are parents not wanting our protagonists to risk their lives fighting the evil government, not merely disagreeing with their life plans).
complicated relationship with sibling? if our main characters have siblings at all, they tend to be 100% loving and supportive, or bitter enemies. Osha and Mae, meanwhile, also have frustration with a clingy sibling, low-stakes fights, wishing you could have a better relationship with them, regrets and attempts to make up, and fierce protectiveness and love despite it all.
repressing emotions, struggling to get over old trauma, isolating yourself or pushing away help? yeah lol what can i say
breaking free of the expectations of your parents/teachers/environment? star wars protagonists often try and usually succeed at fulfilling those expectations instead, though often in unexpected ways.
realizing your idealized parent figure is not perfect? an important step, usually experienced by star wars protagonists in a more dramatic - but much less relatable - identity reveal.
(thanks @flettwin for indirectly rescuing this one from the drafts!)
!! this post is not saying that relatability is the measure of a well-written character. i take issue with this specific criticism which i find disingenuous and weirdly common !!