ChatGPT is a text predictor. You are not asking it for book recommendations, you are writing "some good books are:" and hoping that glorified autocorrect will somehow come up with actual books to complete the sentence.
This effect is compounded by the fact that it is trained to predict text that will make you click the thumbs up button and not the thumbs down one. Saying "here are some books" and inventing makes you more likely to click ๐ or doing nothing, saying "as an AI language model, I do not know about books and cannot accurately recommend good books" makes you more likely to click ๐, so it doesn't do that.
Expecting chatGPT to do anything about the real world beyond writing text "creatively" is a fool's errand.