The question is if we are in a simulation, what sort of computer is running it? What are the laws that govern how that computer operates? How do you get simulations to have a conscious experience? Is that computer a simulation in another computer, and what about that computer…where does the chain of infinite regression end?
Especially these questions are pertinent if quantum mechanics means that reality is “pixelated” and thus a computer simulation.
Electronic computers work because of quantum mechanics. Any computer powerful enough to simulate the universe would likely harness the power of quantum mechanics as well, even more so. Quantum mechanics explains how atoms behave, which is the foundation for chemistry, and as well as electromagnetism and this electricity which is what runs modern computers.
If we are a simulation running on a computer of some sort, then it might not be a computer in the everyday sense and the laws of physics that govern that computer’s behavior might be unlike what we observe, which is all based on the behavior of quantum mechanics. In fact, we might not call such higher reality a computer in the everyday sense at all. In that sense, reality might indeed be something akin to a “simulation”, but not in the sense of being in an electronic machine.