There are also simplifications. We don't spend years in training how to throw a spear well or use a bow and arrow or blowgun, we don't spend years learning how to make needle and thread from plants and bone, nor sew animal hides, we don't memorize long oral poems, we don't cure our own leather, we don't learn the best ways to store ice for the summer, nor how to ride and keep a horse ... I think you get the idea.

Even in the sciences, we don't learn Euclid's Elements but instead learn trigonometry, we learn evolution, so have a single unified field of biology instead of multiple independent disciplines of botany, anatomy, etc., we have solid state devices so few of us know about vacuum tubes.

('We' here of course is meant in the general sense. There are still people who learn the intricate details of flint knapping, or learn ancient Greek to read the Elements, or any one of these topics.)

So yes, there are limits, but either 1) we reached those limits long ago, and solved it by diversification in individual rules, or 2) we are nowhere close to them for our cultural requirements.