In modern polished games, the art team spends a lot of time tweaking things to make sure it looks great and coherent. Most people are not willing to have their agent run for a month to do this work. I don't know if it's been tried yet but I would be really interested to see the result.
Usually a combination of distance and frustum culling (breaking the model down into several that only load when you need to see it) with 4k or 8k textures can make a low poly game ready asset look very high quality