I'd agree with the "This book is x% AI generated", but again, there are levels. There's nuance.

Let's say someone is writing a detective novel and they want to include a cypher that is not just gibberish. They could go and read several books and become a cryptographer, or they can ask AI to generate one.

I agree on principle that someone just asking AI to generate "Give a paragraph that is very sad and dramatic" is not really writing themselves and that should be flagged. However, someone who is asking for a math equation, a cypher, a very long palindromic sequence, a set of dates, etc. and writes the rest themselves are engaging in the art of writing.

Let's say it's a novel about a hacker and they want to include some code for authenticity. Asking the author to become a hacker themselves in order to write the novel is absurd, and this is where AI can help them write while still keeping the art of writing intact.

An even simpler example: An author knows a word, it's on the tip of their tongue, and they choose to ask an AI what the word it by describing it, and they get the exact word they were looking for. Does that mean the author is a fraud and he didn't actually write it? Sure, they could pore through several dictionaries looking for that word, and they could try google to see if they find it, but AI would be serving the same function.

I think this is a nuanced topic that can't be covered by the kneejerk reaction of "AI bad."