I guess we don’t know, but “the universe is a simulation” is a very broad statement. What if the simulation isn’t even for us? What if the simulator is just measuring the distribution of mass and ratios of elements as the universe ages? What if the simulator isn’t even specifically aware of our galaxy, let alone our civilization or each of us individually, and any life is just a byproduct/noise/outlier? I’m not familiar with every bug in my gravel driveway. What if this simulation isn’t even supposed to remotely resemble the simulator’s reality?
Without any evidence I only entertain the idea, but if this is a simulation, I would guess that it’s not for us. We’re such a tiny, insignificant part of the universe. If we were the focus, you’d think that the universe would be leaner and tailored for us, old testament style firmament and flat earth