This is the proper response to the various flavors of nihilism. The world is a simulation, or the universe is cold and uncaring and there is no god, or what if you're just a brain floating in space having a hallucination?
So what?
If the world doesn't exist, but every test you can perform is consistent with the world existing anyways, then so what? Where do you go from there? You'll still experience consequences for whatever you do, everyone else will still experience consequences for what you do (as far as you can tell), so... what has the nihilism or the simulation theory changed?
Doesn't matter what color we paint the backdrop if nothing about the play or the props or the players have changed.
This is basically what many eastern philosophies say. In Budism they fully admitted to the inability to prove the reality of one's existence. At the same time talking about the importance of engagement with reality.
Basically reality exists because we are here to perceive its existence.
Yep, your brain percieves stimuli and generates a virtual internal reality that runs with a tiny time delay between the objective reality and your internal subjective simulation of it. So we live in a simulation even if our universe is the objectively 'real' one, or we live in a simulation of a simulation.
Your personality may also be a simulation internaly created so that you have a way to 'justify' your bodies actions to other entities. Split brain experiments are veeeery interesting.
This is pure conjecture but I sometimes wonder if neuro-divergencies are caused by a fault in the internal simulation via brain chemistry