Shang-Chi was one of the best movies in the MCU, and yes the ****ing dragon rocked. (Seriously that's one of the coolest dragons in the history of cinema.)
Would a completely different story have made it an even better movie? Maybe. Who knows. You could just as easily ask the exact same thing about Endgame, Ragnarok, the Winter Soldier, The Dark Knight, ad infinitum. It's a nonsense question that's impossible to actually answer and irrelevant to the actual merits of the films under discussion.
I don't know why people need to keep implying that the western and the musical are dead.
Will superhero movies no longer be dominant eventually? Yes.
Is that time starting now? Maybe, but the evidence is not as strong yet as some seem determined to claim.
When it does happen, does that mean Marvel Studios will instantly cease to exist and WB will stop making DC movies? Probably not, no.
Genres don't really die, they just become more or less prevalent. And the superhero 'genre' is so wide-ranging in scope, style and subject matter it could literally easily be adapted to any new major Hollywood fad you wanted to adapt it to. And Marvel Studios - existing for literally no other reason but to adapt Marvel characters - will obviously not stop trying to find a way to make Marvel characters work in whatever climate exists for as long as they continue to exist (which is one driving force that literally no other genre has ever had).