I think sometimes we are too hard on blockbuster screenwriters. They are being pulled in a million different directions. It's no wonder any blockbuster turns out good. Don't get me wrong, some writers are just not cut out for dealing with the director and studio stuff in the blockbuster realm. Chris Terrio, for instance, should never be allowed to get near another blockbuster screenplay after Batman v Superman and Rise of Skywalker.
Michael Waldron is still a question mark. Sure Multiverse of Madness screenplay sucked but it didn't suck enough for me to believe that he doesn't deserve another shot. Maybe he'll crush the Avengers movies? We'll see. They don't need a genius screenwriter, just one that can handle all of the blockbuster nonsense well enough.