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Yes, we can render more polys nowadays, but each polygon must be placed for a reason. We could save these polys for more detailed character design, geometric door handles, instead of drawn on the texture, more dense terrain topology and more detailed grass/trees (which are very polygon consuming). Even those polygons are fast degradate when moves far from the camera because of bunch of LODs.
There are lot of rules about creating game assets, and lot of good articles in the internet. That's one of those https://developer.valvesoftware.com/wiki/Level_of_detail
what are you expecting to see?