No you miss the point. But even more you are very very mistaken about the nature of science. All of science including physics and even quantum physics is an approximation, a mathematical simulation, of the universe.
None of it, at any level is actual reality and no scientist (particularly a particle physicist) would ever claim that it is. They would tell you something along the lines of this…. At this time these are our best theories of how the universe works based on our best mathematical simulations and confirm observations, but they are not and cannot be definitive because even if the model eventually matches observation completely that only proves correlation of the model it doesn’t prove that the model is causal.
And this is the point. Simulation is a model, an estimation of a system. As your model becomes more granular it becomes more refined and can simulate an ever increasing minutia of the system but no matter how accurate it ever seems it will forever be just a simulation.
Ergo sequitur it is impossible for us to ever actually simulate a system inside itself in any model that can itself fit inside it. The best we could ever achieve is a very rough approximation based on highly accurate theory and observation, but this in NO WAY implies that the rules of the simulation actually match in any regard the system being simulated. In fact based on the fact that the simulation must be contained inside the universe it must be an inherently incomplete model.
Even more for any hypothetical universe outside our own for which you cannot even make observations. It is contradictory to claim that our universe is both a simulation and that you can make observations here in our universe that would have any basis in reality in any higher order universe.
Even if I grant simulation theory as true, this presupposes that the parameters of our universe are designed to match that of the other. But even we use simulations to explore hypotheticals. There is nothing to tell (and no way to know) that assuming we are a simulation that we aren’t the simulation that is asking the question “What would happen if a universe were based on quantum mechanics?”
