Being nominated for best picture means nothing. Bohemian Rapsody is nominated and that is a straight up bad movie.
Black Panther is good and I think it's fine it's nominated, but it's inferior to both Infinity War and Spider-Verse.
Infinity War manages to build up its villain and Josh Brolin was fantastic. The Villain in BP is gone for most of the movie which completely wrecks his development. It ended up feeling like Serkis was the main villain. The CGI in BP is horrible. Infinity War took a ton of risks and managed to pull together all these vastly different heroes and tones and make them feel like a whole. Infinity War is a masterpiece, whereas Black Panther never rises above very good.
Killmonger has a complete arc where we learn his origins, his goals, his motivations, the realization of those goals. He's a dominating force in the film, and drives not only the narrative forward, but everything about him deeply impacts the main character and touches heavily on the film's examination of the long term effects of colonialism and the Trans-Atlantic slave trade. For you to say "It feels like Serkis is the main villain" quite literally does not make sense.
I agree that Infinity War pulls together a lot of characters and tones, and I think it does an admirable job of making it all flow together with only minor hiccups in pacing. But as I've said before, only three of those characters have anything approaching an arc, and none of those arcs have the depth that is seen in T'Challa and Killmonger in Black Panther.
Infinity War is not a complete story, and it feels almost unfair to compare it to Black Panther, which is complete, well structured, and ACTUALLY daring. So it's kind of funny seeing some of you attempt to make an argument that Infinity War is somehow a better film. I honestly congratulate you for putting up a better effort than most.