I doubt it is so simply and easy like you make it seem. Atm you only see the outside surfaces. Once you start looking inside objects, buildings, ships the number of surfaces is going to skyrocket. I guess ppl envision legs to be something else than just EVA suit like in "X" franchise.
I never said it was simple. So how do other FPP games do it then. I mean, Doom for instance has great textures, how about Fallout 4 or the witcher 3. According to you these games shouldn't be possible.