I am not a lawyer, but am generally familiar with two "is it fair use" tests.
1. Is it transformative?
I take a picture, I own the copyright. You can't sell it. But if you take a copy, and literally chop it to pieces, reforming it into a collage, you can sell that.
2. Does the alleged infringing work devalue the original?
If I have a conversation with ai about "The Lord of the Rings". Even if it reproduces good chunks of the original, it does not devalue the original... in fact, I would argue, it enhances it.
Have I failed to take into account additional arguments and/or scenarios? Probably.
But, in my opinion, AI passes these tests. AI output is transformative, and in general, does not devalue the original.