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.
There is a difference between AI in general and LLM’s, a subset of AI. Text generators like ChatGPT are the latter.