In my opinion, AI is fantastic for worldbuilding. I have been a tabletop DM for a really long time, and I can accomplish the same kind of high quality and substantive work in 2 hours that used to take me 8. Whatever the AI gives I end up molding into something more through more questions.
I will say I am diverging enough from the AI generated content to have it be its own thing, and I am not doing it for content I would be paid for; it’s all purely side projects I play with my friends. I think that it is a super powerful brainstorming tool!!