Hot take, but Milevens should be just as pissed off as Bylers about how this show handled their romance. There's a reason why Byler has so much more resonance with so many fans. For a moment, let's actually put aside the usual ship discourse, which generally focuses on how much more believable Byler was and how badly we got queerbated with that one, and let's talk instead about how lazy Mileven was presented, because I for one didn't find their relationship believable for 2 minutes, and I would argue that I absolutely should have. The reason for this being, that for the entire five seasons the Duffers really relied heavily, just absolutely leaned on the heteronormativity of it alone to sail that ship.
They were not the least bit careful with how they presented their dynamic. Season 1 had its moments of childhood curiosity and wonder where they shared their first mutually experimental kiss, and second season had a sweet moment of reunion, but third had them breaking up as soon as the adolescent novelty of makeout sessions wore off, and a tentative making-up that didn't address the true elephant in the room of Jane having so much catching up to do in figuring out who the hell she is as a person before she can handle who she is in a relationship. Season 4 sees a conflict about Mike's insecurity around the L word that feels like it was pulled randomly from a hat full of romantic subplot tropes, and then being completely hostile and condemning to El in the wake of her violent outburst towards Angela (what happened to the Mike Wheeler that would have protected and tried to understand her) all of which is supposedly remedied with a clumsy motivational speech the Duffers couldn't even be bothered to fucking script, which ended up undermining thematic points the rest of the season had supposedly been trying to establish. And then in season 5 they barely interact. And while all of this is happening, Byler is right there in the background getting fed everything that an endgame ship should be fed. Even Jancy is being treated with a deep complexity that the supposedly central ship could only stumble its way through. What the Duffer's ultimately sold us with Mileven was a relationship fraught with unnecessary drama, repeated and deep disconnection and misunderstanding, and at times, actual resentment.
And why does this suck so much? Because there are critical moments in the story that truly could have been impactful from Mike and 11 if I actually could have believed that they loved each other that deeply. The aforementioned Pizza freezer speech where Mike somehow managed to bullshit his way through giving 11 the boost of confidence she needed to escape Vecna; the moment in the abyss where 11 is fighting Henry and Mike looks up at the mindflayer and knows that his girlfriend, supposedly the love of his life, is going to need support and rallies their friends into a Counter-Strike; the final goodbye scene and their last kiss; the crumbling of their plans to run away together; Mike's revelation about her possible escape; the deep sadness that he expects to carry for life. You can definitely see in these moments, that the Duffers really believed that they had something here. so why was it so hard for them to make so much of the audience believe it? Romantically or as friends, I needed to believe that the love between them was deep enough for these things to matter, and we never got that. Whatever you ship, we as an audience got robbed.