Now that you have read my answer, you owe me $0.01 because your brain might use this information in the future.
In the first case, you found/bought a book and read it. No one can or should make you pay for it, unless you stole the book.
In the second case, you found/bought a book then reprinted it infinitely and sold it for profit, ethically you should pay the author and legally you should be in violation of the law.
Even if you made a machine that ingests and recombines books automatically, and you keep that machine locked up and charge people for its use, it is the same scenario: the machine would be absolutely useless without the original books, those books cost people effort and money to produce, yet you pay those people nothing while the machine is basically an infinite money maker for you.
I hope the analogy makes sense.
When it comes to spam culture sure. But will we ever be there? "AI art" isn't impressive and will never be. It is impressive in the academic sense. Nothing more.