You have farms, temples, villages, larger towns and cities, located in logical places. Geographical features have names in the local tongue, the major ruins have a backstory to them.
All of which could be replicated with procedural generation, you know. You really underestimate what is possible, it's not just "create something that looks like X", especially if you allow the time to do things more
teleological.
Even very basic rules (set or influenced by humans) for procedural generation can come up with more "realistic" (as in coherent within the setting) places than any Elder Scrolls from Oblivion on, though that is admittedly not that high of a bar
The biggest problem really isn't this. The biggest problem, when it comes to creating a landscape/levels that are believable but also look as good as they do for example in Dishonored, is this:
Time.
High-detail 3D models, walls with bricks sticking out, holes, objects lying around scattered, some broken, some not, cups in the shelves, etc as well as more abstract things like the flow of a level. Everything level designers can place by hand according to "common sense" or other rules, can be done by an algorithm of sufficient detail - though again, it might not be just as good, but close (close enough for most people, I'd wager). And it would probably be a thousand times faster than any human. Still, even if you'd guess optimistically, that would still take many minutes. For smaller levels.
Too long to do at runtime.
Which is why I took the Morrowind example. Early age 3D geometry is pretty simple. Way, way less details, less objects, less anything. Or maybe go back another step, to the Heretic & Hexen games (man, I love the art in those games), even simpler.
Now we're at a level of detail that I am convinced is possible to do for procedural generation at runtime, without having to wait for minutes all the time.
Admittedly, I don't think anyone has done that successfully yet. At least not in 3D. Only a matter of time, though, IMO.