There are so many failed attempts at making a stage musical into a movie over the last decade or so, and those are more traditional shows (Les Mis, Phantom, Into the Woods, Mama Mia, Rent, The Producers). The more esoteric ones fail even harder (Cats, Last 5 Years). Chicago worked, but it sat in a perfect middle ground of a film-friendly story with a clever character motivation that made the corniness of theater make perfect sense.
Classic musicals (and the associated movies) have a much slower pace which lets the story breath after a song. There’s a pause, narratively and in presentation, because the song essentially ends the scene. They talk building to a song, they sing, the scene ends, and there’s a slow fade (or lighting change) with an interlude, and the cycle repeats. Original movie musicals, like Anna and the Apocalypse and Disney films, build that pacing into their scripts. That’s why they work.
Modern musicals don’t do that. They’re written without as much (if any) breathing room. There’re more songs, packed closer together, with little if any talking in between. Songs can hit at the beginning or middle of scenes, with dialogue covering transitions between scenes. It means adapting the screenplay to add pauses that hinder the original pace (making things feel slow—like Mama Mia), or ignoring that need for breath and making the film feel muddled and unorganized (like Les Mis).
They can film any musical, however they want, but some shows by their very structure mean they can’t be good “movies” and need to remain “on stage.” Hamilton is one of them.