the idea that the mcu world has become unable to detect bullshit after what happened is kind of a dead end narratively. part of the appeal of marvel vs dc is the world stays relatively ordinary, no matter how used to nonsense people get. and why not just lean in to the ridiculousness, rather than having such a dry premise for mysterio's illusions? make it so wacky you almost can't believe it, so you're forced to accept it because who would make up shit that weird. like i said, I get the whole "people will believe anything" angle, I just don't think thats a statement that has real meaning