...if everything was randomly generated, we'd end up with a very big world that is also pretty generic in boring in most parts like Daggerfall...
Actually, not attaking what you said, just makign a point, there IS a place for randomly generated environments, and no that's not the garbage
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Take for example, yu have a big world, of course the towns and settlemnts are hand place, the paths are preset, all dungeons have a fixed place, you get the point. Now in between you have a forest somewhere, you hand place the edges of the forest and a zone in between is randomly generated. So every time you enter the forest it just randomly generates it, this way the forest can be very large and doesn't need to be fully hand made. If there are ruins in there they become set islands in this randomyl generated lake.
Or take a desert, you can have the whole desert randomly generated with preset areas in there. This would actually make sense as deserts move. Or fields of grass and flowers, they'd oft course be set to follow a certain pattern so a field of lillies doesn't suddenly become a field of sun flowers.
The actually landscape does NOT need to change necessarily but the setting in there changes. This way it can save a lot of time for hand placing certain environments but generate them as you go.
The actualy problem there is most random generator engines don'T have enough to chose from to do anything good. You only have so many set pieces, that limits what you can make out of it. Plus the engine would have to be "trained" to make certain combinations while preventing conflicts like a cactus growing in the middle of a evergreen forest or two trees intersecting each other. However all this is possible but like everything good in games it needs actualy WORK to get it right.