Maybe this is the optimal timeline and it just doesn't look that way because we're still in the middle of it and not at the end.

Yes, the US nuking Japan was horrific - but maybe we'd have had a much more brutal WW2 with half a billion lives lost if not for mutually assured destruction keeping it in everyone's pants.

Yes, Hitler was horrific, but maybe the world needed a wake up call for the importance of at least some form of diplomatic structure like the UN and things like human rights observers.

Yeah, Trump is scary as shit in what it might mean for Western democracy. But maybe this period we're in right now serves to push us forward to more modern democratic principles and protections suited to the modern age and not 1776.

Sure, AI misinformation and deepfakes are concerning - but maybe the proliferation of BS to an ad nauseum degree ends up undermining existing misinformation ops around things like vaccine denial or conspiratorial thinking where people currently gravitating to "doing their own research" online become better inoculated to BS by sheer volume of exposure to things they increasingly find they can't trust.

We only see the means, not the ends or their possible variations.

So even if there are time travelers, perhaps they are quite committed to what seems a mediocre timeline because the odds just happened to play out in such a way that our misery paved the way to their paradise.