which experiment proves the universe uses lazy evaluation? this seems like interpretation
"Wheeler pointed out that when these assumptions are applied to a device of interstellar dimensions, a last-minute decision made on Earth on how to observe a photon could alter a situation established millions or even billions of years earlier."
https://en.wikipedia.org/wiki/Delayed-choice_quantum_eraser
That's not to say that this is "proof" but I think this is where the notion is most directly apprehended.
After almost a century of discussions between smart people, the physics consensus has steadily inched away from Copenhagen.
That said, that doesn't mean lazy evaluation isn't happening. You just can't use lazy evaluation to "explain" wavefunction collapse, it's more the other way around, that collapse can be a lazy evaluation trick. It'd describe only this simulation and say nothing about outer reality (thus no longer works as evidence for or against the simulation hypothesis, it's just a consistent part of the story given that it's true).