Spend a couple of years without the money and limelight and a lot of people might change their minds. That being said I don't think getting the gang back together will magically fix this shitshow. I still think you might have some individually good movies, but it's never going back to where almost every movie was good to excellent.
Who knows. They are all going to be cashing MCU checks for the rest of their lives. Evans once said he was done until they started waving bigger and bigger checks at him so maybe not.
Getting people back together won't fix anything. The people calling the shots need to be flushed before anything decent can be done, and that isn't going to happen.
Besides, they are all getting old. RDJ looks like he's got 7 toes in the grave, and the rest would be pushing 50/post 50 by the time they got a project going. Scarlett Johansson was in her 20's when she started MCU. She's be well into her 40's for any project....no thanks. They'd have to digitally deage her and debutt her, too. She was a lard butt in Black Widow movie.
And besides, do we really want to see people shooting laser beams out of their wrists and telling dumb one liners all the time and where no serious things happen to anyone ever? They could multiverse in Iron Man and Black Widow, but that would be the same as if they didn't die at all.
Further, without any changes at the top, we'd just get dumb movies with characters we used to like. See: the last Dr Strange movie.
They got 20+ movies out of it, perhaps it is time to take the MCU out behind the shed and hit it in the back of the head with a shovel.