By default an AI will draw from its entire memory, and so will have lots of different influences. But by tuning your prompt (or restricting your input dataset) you can make it so specific, it’s basically creating near perfect clones. And contrary to a human, it can then produce similar works hundreds of times per minute.
But even that is beside the point. Those works were sold under the presumption that people will read them. Not to ingest them into a LLM or text-to-image model. And now, companies like openai and others profit from the models they trained without permission from the original author. That’s just wrong.
Edit: As several people mentioned, I exaggerated when I said near perfect clones, I’ll admit that. But just because it doesn’t violate copyright (IANAL), doesn’t mean it’s ethical to take a work and make derivatives of it on an unlimited scale.