The problem is not with 3D asset, the problem lies with the developer always rendering everything. Because some of them ... nah, all of them are lazy bastard. They didn't bother making it efficient at all. 1 render pic might vary between 500kb to 2,5mb. And when the character moving slightly, a new render being made. That's why for many many games, 1 event scene could use about 100~200 pictures and bloat like 600mb size, and they are proud of it ... what a joke.
I'm from 3D animation industry for tv-show, we have to be efficient or we might missing deadline. How to make an episode of 20 minutes show with 25fps only had 2 weeks to render them all. 20min X 60 second x 25fps = 30.000 images must be rendered in 2 weeks. To achieve that, we have multiple model on 1 character. If they far away, we have low res text & polygon model for each. When only showing head or body on conversation, then we have legless model for them. We're separating rendering the shadow and the scene and mix them up later in editing, twice the rendering, but twice more faster than rendering them all in one. Weird, but it's true.
Very contrast with porn game developers, who just put them all high res model, then 1 render might take 5min~4 hours, depend on their machine. They are so barbaric, savages & retard. I know the nature of the W.I.P. between mine & them are different, but they aren't bother to make their pipeline more efficient, especially in the 3D part. Rather than thinking, which part to be cut out from the render, instead they prefer to upgrade their graphic card. This is what I called killing 1 mosquito with a nuke.
So I disagree when you say the problem with 3D asset ... no, the problem with the 3DCG's Developers. They could just make 1 very high res background, and render the character differently. The very same thing like 2DCG games. Only the character have multiple renders, and this will decrease the size significantly.
