Though this would be an ambitious project, if it were done it would drastically increase the life of GMod.
In short, what it would involve is getting maps about 60-100x bigger (current ones are about 1 km), and a physics engine capable of handling about 20-40x currently possible. If this was done, then GMod could reach it’s real potential. For example
-Huge “wars” with 40v40 player schemes (40 tanks v 40 tanks etc…)
-The need for things that actually go fast (noclipping across a 60km map takes awhile compared to a 600km/h jet)
-More builders per server, with less lag
-A more realistic Gmod.