For me, if I want to go for breadth (quantity), AI is fine. For depth (quality), I have to come up with it or commission someone really skilled at their work.
I take Elder Scrolls II: Daggerfall as an example. The massive scale of its world map was ultimately procedurally-generated (i.e. AI). The locations important to the main quest was hand-crafted and generally of better quality.
I pretty much only world build in TTRPG’s. As a result I use AI a lot in world building, for everything from landmasses, to city layouts, to individual NPC’s. Because by the time I get down to the details of the story, the players choices have shaped the story being told, and I no longer have to world build, I just react as the NPC’s.