Stephen Hawking's argument against the thesis of "The real world is a simulation" was that if we WERE in a simulation,if would be rather
entertaining for our masters to see what happens when they tinker with the laws of nature which does not happen.We do not see any
anomalies in the laws of nature.
This being the case,if we ARE in a simulation,what is stopping our masters to conclude that they are in a simulation too.
Thereby this goes on till infinite number of cycles....
hence we conclude that either there are infinite number of simulated worlds inside each world and we are at the bottom of the chain as we obviously are not controlling another world
or
our world is not a simulation.