Exactly, so in the "dystopian" future, people just use AI to write the books they were already having a ghostwriter make.

If the books are original enough to be perceived as not-AI, the mind behind it will be creative enough to make the AI origin moot.

Originality is an interesting thing.

Books are a physical medium of organizing and distributing information by gluing a bunch of flat papers between covers. Properties like originality do not follow from the physical medium itself.

Publishers of travel guides in book form use the physical medium as an instantiation of the class of "interesting coffee table adornment expected to contain wit". Does that imply an expectation of originality? I would argue it does not.

Publishers of speculative science fiction, on the other hand, instantiate objects of the class "examinations into the human condition using technology as a lens". For this class, the use of LLMs is an abomination.

There are other subgenres of science fiction, of course, for which these sensibilities would be misplaced.