A lot of the best Marvel movies are really other genres wearing a marvel skin

Look at Captain America: The First Avenger. It's a pulpy world war 2 film, really. If you took Captain America out it would still be a fun film. Captain America: The Winter Soldier is a spy thriller

Ant Man is a heist movie, like Oceans 11. Guardians is a sci fi comedy.

After a while they started to all just become "Marvel Movies" and that's the point they stopped being nearly as fun imo

A lot of them are only "Marvel Movies" in their final act, which still leaves a lot of room for fun genre-surfing and -bending, before they have to get back to the business of, "This is part of a franchise." But even on that note, I don't think they get enough credit. Phases 1-3, Marvel et al. managed to wrangle a dozen films of varying genres, working through the stories of just as many main characters, into a single series with a coherent, overarching narrative. It was the biggest spectacle ever created in the Spectacle Industry, yet with a handful of examples of genuine cinematic sublimity (if not entire films, at least a few scenes), to boot.

And people would rather hate than just ride the wave.

Right, most of the context of who the original characters were and represented in the comic books are washed away in the movie versions- it's just a marketing thing that draws people in.

Batman and the different actors and directors over the different versions of the franchise is another example.