One example. I have a friend who has spent hundreds of hours on a campaign setting. He has original maps for every city there, extensive notes for encounters, questlines, lore. But it's all handwritten or hand drawn in his notebooks, not digitized, and not accessible to anyone else.
Typing these up and formatting them properly would be a massive value add. He's considered doing it but finds the amount of work daunting, given the other things going on with his life right now.
AI could make self-publishing this kind of thing way easier.
Now, in my opinion, using AI to compile notes is acceptable. That's not generative AI and it's not stealing anything. Although I would say it would be better to actually compile the notes yourself (since you have to type all that info in anyway), or hire someone to do it--but I accept that there are things that would get in the way of doing either of them.
Using AI to add details to those notes, and then making them pretty enough to sell,
is stealing, though. So nope.
Because quite frankly, I don't know how detailed those notes are. Maybe your friend is the sort to go into excruciating detail--one of the GMs at my table has actually made a language, or at least some vocabulary and certain phrases (I don't know if they've developed grammar). I've gone fairly deep into completely unnecessary details for my settings. So I believe your friend's notes could be very extensive. But a lot of GMs don't have extensive notes. (And that's ignoring that a lot of GM advice is to only prep what you need, or even how to get away without prepping.)
So slippery slope time: how many of these AI-assisted self-publishers will be feeding the AI reams' worth of written information, and how many will have a few ideas and let AI do the rest? Because a
lot of people have a few ideas
; relatively few have a book's worth of material.
And that's still ignoring the visual art needed for such a book. If you can't draw and don't have the money to hire an artist, you could at least shell out a few bucks for clip art or spend some time looking for royalty-free non-AI art online.