Depending on the level of Demon (there's a hierarchy), they have different levels of knowledge. But even the "lowest" ranks are a hundred times more advanced than the most advanced Zevism humans. They don't need to "snap their fingers", they already know.
It took the high-ranking demons hundreds of thousands of years to get to their level of advancement. Do you think newer humans who develop their magnum opus could ever get even anywhere near their level because they've paved the way, or is this basically impossible. Or what I mean is, can we get their significantly quicker since we didn't have to figure everything out for ourselves or will we always be bottom of the barrel? Until newer souls develop? Does rate of development plateu eventually?