Laws of physics are not some deep mysterious algorithms built into the universe when it was created, they are human approximations of the infinite complexity we observe. As long as the universe is at least somewhat predictable and not completely random, it is possible to construct a series of increasingly accurate ways to predict its behavior. If the universe included predictable dragons after half a second, these approximations would, too. In fact, the Navier Stokes equations happen to describe so many dragons, there is still an open Millennium problem related to them. If the dragons appear unpredictably... well, then, it's just like the universe we already live in, where the unpredictability is everywhere (if you doubt that, please tell me the results of tomorrow's lottery).

So no, our universe is not particularly simple. It's mostly, to quote a historian, "one damned thing after another".