I think is a very rational take indeed, and while it means that the simulated nature of our universe cannot be disproven (nor proven), it does mean that we cannot simulate a universe like ours.

But the simulation theory does rely on the reasoning that there is a (possibly infinite) chain of simulated universes in order to argue that it is more likely that our universe is simulated than not. But if we cannot simulate a universe like ours, it also becomes pure conjecture to suggest another universe can, and therefore the chain is broken.

In fact, the universe “above us” would need to have mathematical rules that are beyond what we know to be true. At that point, even the discussion of determinism vs nondeterminism goes out the window, because our understanding of truth would no longer apply. But calling the/a/any universe a simulation implies knowledge of determinism, otherwise it no longer fits our understanding of algorithm. So if you believe the universe is a simulation, you may as well say that you believe in spirituality (not the hand-wavy non-scientific kind, but the kind that acknowledges an understanding that is at a higher level than ours). I think it’s hard to argue against a higher-level understanding beyond ours. But calling it a simulation has implications that don’t seem to hold. So maybe calling it spirituality is actually the fairer description.