I think modern people have so much faith in this reality, they'd have little chance accepting that it is other than it seems. Any evidence would have to be stark.
Actually, physics supports the probability that we live in a simulation. Our universe has the highest limitation of speed and the smallest units of length and energy.
Neuroscience, psychology, public opinion polls, and internet forums demonstrate that we do.
The problem is, the nature of this style of simulation, as opposed to the Bostrom theory ("the" simulation theory (singular, there can be only one)), makes it (nearly) impossible to realize.
This is both tragic and hilarious, especially since we have extensive knowledge of this flaw.