Golf is played in 3-D. Unfortunately, there are lots of architects who try to reduce it to 2-D ... making surfaces almost flat where they expect the ball to land, so that the bounce doesn't have to be factored into the equation.
I wish this were more true. I got into disc golf a few years ago, and one of the earliest appeals to it is how much more often the third dimension comes into play than it does in golf. (In reality, disc golf can almost be considered 4D, because discs can curve two directions in one throw, you have to consider time too… how long do you want a disc to turn over to the right, and how much do you want it to fade out left at the end…).
Unfortunately, far too many golf courses present more of a 2D problem. Golfers rarely have to consider height - whether to play the ball along the ground, in the air, etc. It's simply a matter of point-to-point navigation, with little concern of what's in between.
Unfortunately. The better the course, the more likely the third dimension comes into play, but all too often IMO golf is a 2D game.
P.S. Not quite the same definition of "3D" that you used, Tom, but I think you will know what I mean.