I'm absolutely positive that the vast majority of fiction is or will soon be written by LLM. Will it be high-quality? Will it be loved and remembered by generations to come? Probably not. Will it make money? Probably more than before on average as the author's effort is reduced to writing outlines and prompts, and editing the generated-in-seconds output, rather than months-years of doing the writing themselves.

I think that novel writing and reviews are types of writing where potentially AI should eventually surpass human writers, because they have the potential to replace content skillfully tailored to be liked by many people with content that's tailored (perhaps less skillfully) explicitly for a specific very, very, very narrow niche of exactly you and all the things that happen to work for your particular biases.

There seems to be an upcoming wave of adult content products (once again, being on the bleeding edge users of new abilities) based on this principle, as hitting very specific niches/kinks/fetishes can be quite effective in that business, but it should then move on to romance novels and pulp fiction and then, over time, most other genres.

Similarly, good pedagogy, curriculum design and educational content development is all about accurately modeling which exact bits of the content the target audience will/won't know, and explaining the gaps with analogies and context that will work for them (for example, when adapting a textbook for a different country, translation is not sufficient; you'd also need to adapt the content). In that regard, if AI models can make personalized technical writing, then that can be more effective than the best technical writing the most skilled person can make addressed to a broader audience.