I used to think about this a lot, and I came to the conclusion that it doesn't really matter either way.
The universe already seems like a simulation in its own right. It's governed by preexisting rules (e.g. laws of physics, laws of thermodynamics) similarly to how any computer simulation would be operating under pre-programmed rules.
It's not like we're going to be able to observe or communicate with the beings outside of said simulation, if we were somehow able to prove we we're in one to begin with, so why worry about it?
I'm no weird nihilist or anything, it IS an interesting thing to think about. I just think that it ends in the same result regardless of the true answer.