Dude, T'Challa inspired thousands of black children if not millions. To you, him playing the role while suffering from colon cancer may have been a passive, reactionary performance, but it was powerful enough to leave a lasting impact on people of all ages. There WILL BE NO BETTER T'Challa than Chadwick Boseman, just like despite Joaquin Phoenix winning an award for Joker, there will BE NO BETTER JOKER than Heath Ledger.
The Joker still made $1,000,000,000, though. I have stated already that the character is important, so there is not a need to rehash what he means to the kids. I have not stated that is performance is unimpressive either. I believe that there are plenty other actors who are able to impress in the role, too, and how are you saying that it is important for the kids but not wanting them to have another big screen version of the property?