To be honest, the mountains are the last place you'd ever find me in this game world. They are just empty, flat and void of detail. Yeah, okay, the spare bush here and there, but there's just nothing up there but ugly textures and very visible polygons. They feel like they were placed in there early in the map concept part of development and nothing was added since. Very poor part of the world for sure. And yeah, they do feel pretty small when climbing up, but I will admit you get to the top of Chiliad in a modded fast car then drive straight off a cliff, you feel that verticality and height.
Accept your thoughts but that was a bit harsh I think.
Well they still have wild animals on them and thats a part of a detailed, living game world don't forget that. And it's fun to drive on them/ Basejump and so on.