Difference with star wars is that Luke, Leia, Han, and to a lesser extent, chewy were the stars and main characters. That was an ensemble. We saw Leia doing her own deal to start the movie then we are introduced to Luke then Han. In ESB like gets knocked tf out and we see han save him, when they leave hoth they go separate ways but they are working on their own goals.
Everything in BP revolves around T'Challa. T'Challa retrieves Nakia from her mission. T'Challa goes after klaw, T'Challa brings Ross to Wakanda, T'Challa talks and convinces M'Baku to help his cause, and T'Challa is driving the confrontation with Erik. The difference is that his supporting cast also do more than stand in the background, but not enough to call them an ensemble like in the x men movies were the team dog piles magneto and injects him with the x gene cure.
It's very clear who the movie revolves around, and it also shows in IW and EG. People weren't cheering Because they saw Okoye. IW trailers used T'Challas chant to hype the movie. The BP trailers didn't get extended screen time to the support Cast..
Again see blade. At the time one of the most successful superhero movies during the time and he was the main focus as well as his name on the title, snipes is also still alive and they 100% sidelined him in Trinity.
It doesn't matter if T'Challa had more screen time, the same results would of happened UNLESS Chadwick before passing said "RECAST ME OF I PASS" which I feel like it's obvious he would want that based on his Interviews and what he has said about characters or roles he has played