The ground game concept is not exclusive to green approaches, it is also a factor on the fairways. Contours make a course more interesting, because you have choices where to bounce the ball off of. You can do things on the ground that you cannot do in the air (and vice versa, obviously, so you want both options).
If you play target golf, then the objective is to hit a 150 yard shot - no matter what the golf course looks like. In target golf you are playing yardages, not courses. The only fun part of that is figuring out the right yardage to play from a given position on a given hole, but on your home course that is pretty much done with after a couple of rounds. Every golf course in the world - be it a Top 10 hallowed track by a famous architect or the 9 hole Mom & Pop outfit round the corner plays the same through the air. Well, there may be different wind conditions and elevation - but the air is really mostly the same everywhere
Ulrich