We shouldn't hold individual humans and ML models to the same standards, because ML models themselves are products capable of mass production and individual humans are not even remotely at the same scale.
If you write that book, chances are you will gain some fans that are also fans of other authors in that genre.
If ML models write that genre, they can flood that genre so full that human artists won't be able to complete.
It's not even a remotely equivalent scenario
It's an interesting predicament. Assuming these stories between person and machine are indistinguishable and of same quality, then the difference here is the ability to scale. Without giving bias because of humanity reasons, why should we give entitlement to output derived from a human over something else of same quality?
I hate making analogies, but if we make humans plant rows of potatoes, should that command a higher price and seen more valuable than planting potatoes by tractor 20 rows wide?
No, we should absolutely be giving bias to humanity. Flesh and blood humans matter, their lives matter, their thoughts matter and their work matters.
Machines are tools for them to use not entities given the same rights and same consideration.
I reject your whole premise.
People have the choice to continue making stories and they'll have a fanbase for it and always will, because that's ultimately apart of freedom and choice. Many are less what I'll call purists here, and don't care about how it came to be, they just want a quality story.
What you're loosely proposing is art being a protected class of output, when we have tools that can match and soon with the potential to surpass. Is that not a terrific way to stunt what you're trying to defend?
For transparency, I am an advocate for human made art, but I am against stunting tooling that can otherwise match said creativity. I see that as an artform in itself.