Jack Hardiman’s review published on Letterboxd:
Definitely enjoyed this less as a film and more as a showcase for the two actors on the poster. Viola Davis is as good as Viola Davis tends to be when tackling these sorts of roles, but here she plays second fiddle to the late Chadwick Boseman, who gives his all in his final performance as a young, ambitious blues trumpeter. I haven't actually seen much of Boseman besides his contribution to the Marvel movies (which I'm less than keen on) and Da 5 Bloods, in which his part isn't exactly front and center. Here, though, the man gets plenty of screentime to shine, and shine he does; his presence is spellbinding, often to the detriment of the other cast members and even the film as whole. Around such a pitch-perfect piece of acting, it's hard for anything else to look good. Unless you're Viola Davis, obviously.
Outside of the performances, there isn't too much to write home about here. The story, adapted from a stage play, seems quite weak to me, with all but two of the characters (and nearly all of the relationships) left unexplored and one scene moving to the next without much consequence or sense of purpose. As a narrative, it serves mainly as a vehicle for themes of racial inequality and a depiction of the black experience in America pre-Civil Rights Movement, which are undeniably handled with heart and sincerity. I'm also a sucker for movies where all the action takes place in a single room or building over the course of one day (see 12 Angry Men and Reservoir Dogs), so it's not like I didn't enjoy the film overall. It just left me wanting more, especially from Ma Rainey herself, whose story and personality is underdeveloped and thus ends up more intruiging and entertaining than genuinely engaging.
Ma Rainey's Black Bottom is Chadwick Boseman's film through and through; if he wins the Oscar, I can't see anybody complaining. Worth the watch for that alone.