It shouldn't make a huge difference, actually. Things like trees and faces are already rendered to a complexity beyond where it's reasonable to create them by hand. That's why there are 3rd-party utilities to render these things easily, with some simple inputs, like plugging a formula into a fractal generator. You don't have to hand-design an NPC's face any more than their parents had to piece their fetus together. You plug in the DNA and the code does the rest.