If you had a machine that created a window through which you could see the future, and in the future you wrote down the winning lottery numbers and relayed that information to your present self before that lottery number was drawn.
However, in your present selfs excitement, you turn off the machine before your future self wrote the winning lottery numbers into it for your past self.
What would happen?
I get what you mean, but I have to disagree a bit. The slice of the multiverse we’re looking at is special because we’re looking at it. It only makes it irrelevant if the slices are treated as fully replaceable.
Take for example Invincible. The comics & series focus on a young superhero who could have become incredibly evil, but didn’t. The multiverse is used to highlight this: it shows alternative versions of him that did become evil, and it even says that most alternative versions did so. This makes the version of him we focus on that much more special, and allows for interesting character progression through being confronted with his fears.
But it only works because of the restraint of the writers, never showing us another good version of Invincible, only focusing on evil alternatives.
Invincible can’t move between the infinite timelines though, and no storyline is hanging off of the important changes he makes those timelines by travelling through time/dimensions. He’s not “saving” anyone by jumping through to another universe
Yes, that’s the restraint the writers are showing. That’s my point: the issue isn’t the multiverse aspect itself, it’s the replacability brought on by unrestrained multiverse implementations.