Yes, it looks computationally difficult to us, with what we know, to make a universe simulation. But if we're in a simulation, everything we know is a parameter

Yes, it looks computationally difficult to us, with what we know, to make a universe simulation. But if we're in a simulation, everything we know is a parameter of the simulation. We know nothing about the energy/computational capabilities of the simulation host system. So the main argument made here assumes the conclusion: if we're not a simulation -- our perception is accurate the 'real' limtis to computing -- then we're not in a simulation.