I think using AI art and disclosing it could be fine in principle. But in practice, it’s not.

The sad reality is that image generation AIs have been trained on massive amounts of copyrighted material without asking for any permission nor compensating the artists.

Like, imagine a company took everything you ever wrote, every single story you were proud of, fed it to a large language model, and then that model, which is now capable of parroting in your writing style, is put online for everyone to use. Then people go to the website and create writing in your style and compete with you on Medium and elsewhere.

That's what happened to visual artists. (It didn't happen to musicians because AI companies are afraid of the notoriously litigious music industry.)

But if there is an AI image generator out there that is not based on copyrighted material used without permission, then I think it would be fine to use it if you disclosed that it came from an AI :)