Man I want to have your optimism. But uh I think we've gotten too far away from the original point of superhero fatigue. Obviously if the last movie you've seen was Endgame and then you go into Doomsday you're not gonna have fatigue. Doesn't change the fact that phases 4 thru 6 only had 4 good movies out of 14. Lets set aside my (poorly worded) point about being required watching. If you're just keeping up with the movies you'll have to sit thru 10 bad ones and shit gets tiring.
And that's the point that I really want to make. The pile of bad movies don't drag down the good movies. No matter how much trash Disney pumps out, people won't get tired of superheroes altogether.