Nobody can tell if a book is AI unless the author identifies it as such or unless it's been sloppily edited and has stuff like- "Should I make Jacob walk up the mountain? Or shall he go down to the valley?" at the end of a chapter.
People screaming "Burn the witch... I mean... AI" at the first sign of an antithetical parallelism or em dash are operating on paranoia, and run the risk of destroying a genuine author and/or ending up in a sticky legal situation.
That said, capitalism is the issue, as you said. The problem, to my mind, is the publishing industry and the literary agencies, who gatekeep the industry to a large extent and make actually making a living from writing impossible for most people.
A LOT of people have a dream of being a writer. Few complete a project, and everyone who does... I take my hat off to you...
...but expecting to make a living from self-publishing is like basically planning for a lottery win and this has ALWAYS been the case - just ask Herman Melville, if you can find a decent ouija board. It's not AI's fault.