The Division, Watch Dogs and Wildlands beg to differ, Wildlands especially has so much variation in environments and biomes it isn't even funny, it's basically a miniaturised Bolivia. Additionally, games like Origins and Odyssey are set in a period of time where you'd only see one type of architecture be prominent, you weren't going to get several different styles of building in ancient Greece. And Egypt basically had 2 styles which would be Greek architecture, and ancient egypt architecture (which was ancient even by the time Origins is set in).
But what is there, is immaculately modelled with a lot of care and attention put into the world, things make sense in the way that there's a logical reason for something to exist, you won't find a farm without a river stream, you won't find a quarry without a mine and waste dump with workers etc etc (Karak from ACG talks about these in his "walking the walk" videos for these games) which is why they were able to do the discovery tour mode for those games. Them being "by the numbers" games (which I totally disagree with)...does not mean they are not crafted with care and attention in mind.
Long video (it's timestamped so atleast watch it for 4-5 mins) but it completely deconstructs the argument that these worlds are not made with artistry. Their world is full of activities where the NPCs interact with the environment in a logical and appropriate manner. It gives their games a lot of life and unique look.