The ground is a vital element in any flight simulation. Be it Falcon 4.0, MiG Alley or Longbow 2, this feature is bounded by design decisions and technical issues. Eye-candy is constantly pushed in flight simulation but ground warfare simulations such as M1 Tank Platoon, Panzer Elite and assorted helicopter sims are far more demanding by necessity.
Terrain presents tactical challenges for the player and technical challenges for the designer.
A game designer needs to ask questions about what the simulation is trying to achieve and how much ground detail is required to deliver the experience. And this is just the ground aspect. These are details which are not really necessary for a fighter sim and are often fudged. From birth our brains have been learning how the real world looks, no matter how good the CGI, it is always possible to tell that you are looking at a fake. Team Alligator Hi-res mesh mesh, small textures and high object count.