I'd generally retcon the X-Men from existence itself.
Best post in this thread.
Years before Scott and Jean were even born, Xavier and Magneto sit by a fireplace and discuss mutants. Xavier thinks mutants should live in peace with humans. Magneto disagrees and crumples his wheelchair into a ball. With Xavier gone, Scott remains homeless, Jean overdoses because the voices won't stop, and Beast goes to prison for life after he snaps and murders some jock who kept calling him Harry Hairyhands.
Magneto tries terrorism for a while, humanity goes lol no and bombs him to death.
All is well with the universe.