Not exactly. Humans concatenate previous written sources to some extent, sure. But we also concatenate life, which is too chaotic. At a certain level of abstraction, pretty much every life has been lived before, but reasonably, every life is unique and every author or artist has unique experiences that go into what they do. That is the major difference. The sum of all fiction is a huge library to cut and paste from, but life renews trends in fiction. What the artist has seen, both art and the world, matters.
As an example - William Gibson is credited with creating the cyberpunk genre. This is a bit reductive, but Neuromancer is a different work compared to what came before it, though it draws on other sources from before it. Nevertheless, the genre didn't really exist before... 1970 at least, in any real way. Suppose you train an "AI" on the sum of fiction from before then. Could it have written a cyberpunk novel? I don't think so. It took a bit of inspiration, a life, a certain odd combination of optimism and pessimism about the way we are headed. Of course, now ChatGPT can churn out cyberpunk novels all day, because there is something to draw from and combine with other works. But there aren't ideas there. So yes, there is a significant difference between a creative human mind making an artwork and an expert system producing a prompted piece. They could both be useful things in their own way, but they are dissimilar in very distinct ways. I think it will probably be interesting and enlightening - not to mention quite surreal - to read a book written by an AI that has its own experiences to draw upon.