This is a fundamentally flawed way of questionning, "knowing all the laws of physics" is probably impossible to achieve, but we still produce accurate predictions for a lot of phenomena. You can see that we do in fact "replicate" (predict would be a more proper term) things despite not knowing all the laws of physics: weather, movement of the stars, cooking time for a browned piece of bread...
I was replying to someone asking if it was "exact"… and no it isn't… You listing a bunch of simulations, that are notoriously not 100% correct proves my point, thanks.