I posit a world simulation that is fully faithful to science. It follows then that the scientists of the first simulation are able to create similar simulation

I posit a world simulation that is fully faithful to science. It follows then that the scientists of the first simulation are able to create similar simulations - and so on, until we have simulations "all the way down". I refuse to accept that the processing burden of infinite regressions of simulations can be met by the original simulation.