Nope: there is sufficient evidence that the Earth is not flat, but there isn't sufficient evidence that causality doesn't exist. That is the difference. There are some counterintuitive theories, like QM or relativity or, maybe, round Earth, but all of them have been supported by a lot of evidence, there were actual experiments to prove them, etc. And these theories appeared, because old theories failed to explain existing evidence.
Can you name a single real-world example where causality doesn't work?
And you're not the first LessWronger to think that if your idea sounds clever enough, you don't actually need any evidence to prove it.
"Species can't evolve, that violates thermodynamics! We have too much evidence for thermodynamics to just toss it out the window."
Just realized how closely your argument mirrors this.
A self-modifying AI is built to serve humanity. The builders know, of course, that this is much riskier than it seems, because its success would render their own observations extremely rare. To solve the problem, they direct the AI to create billions of simulated humanities in the hope that this will serve as a Schelling point to them, and make their own universe almost certainly simulated.
Plausible?