Two things here. First, you have to know what to ask an LLM. A book on a subject is already organized with all the information that could be returned by the same prompts that would lead to it. The prompting effort was essentially already done by the author and publisher.

Second, you’re getting a more compressed and lossy form of that information from an LLM, unless you go to such efforts that it’s be easier to just read the book. It’s akin to a conversation where a friend asks you about a book in finer and finer detail until you either recite the book for them word for word or direct them to just go read the book.

So, I don’t think LLMs are replacements for reading books. They’re complimentary.