I might be the only person who didn't hate Quantummania. I thought it was actually a return to form for the MCU; we forget this, but most MCU movies are actually just okay: not bad, but not terrible either.
I think that multiverse stuff works better if you care about what's in the universe. We care more about Earth if Iron Man is still alive and has a family waiting for him at home than if he's already dead and gone. Marvel should have focused on building up likeable characters before diving into this multiverse stuff.