Right, but in the present case we have exactly what you're describing—a story, almost fully written by AI but with some human cherry-picking in the mix. And readers are finding it a phenomenal story and then wanting to vomit retrospectively in learning about the authorship. It just seems patently obvious to me that this is not where the sentiment is going to stay—it will hit the margin, like the people who decide to not own a cell phone, or those who would rather listen to analog audio; there will be a market for it but it will exist at the margin. Eventually, especially for young people, more and more of what they consume will be AI generated and they won't care because it's indistinguishable from human work.
Or, I digress, it will be distinguishable from human work but because it's so much better than anything that a human could have ever created. These AI tools that we have now are as dumb as they will ever be. If we ever reach AGI or superintelligence or whatever—or even if not, even if these tools just advance for 10 more years on their current trajectory—it's easy for me to imagine some scenario where the machines can generate something so perfect to your liking that you just prefer it to anything a human ever would have created, storytelling and all.
You can take the general case where AI can just generate a better movie than a team of humans ever could plausibly generate. After all, AI doesn't have any of the physical constraints of a movie studio—the budget, the logistics of traveling from location to location, the catering, the fact that the crew has to sleep, has to coordinate schedules, all that. AI, with some human involvement or not, could just keep iterating on some script on a laptop overnight until its created an optimized version which is more satisfying to humans than any other human made movie ever created. Or in a narrow case it could create the perfect movie for you, given what it knows about you and your interests. All human movies would look inferior.
For my kids, who I'm sure are going to grow up in a world where this type of art is embedded everywhere—and where the human version is almost certainly going to be worse—I don't think the desperate cries to see the last scrap of human ingenuity will mean anything. All of these people throwing rocks at Waymos and others boycotting companies for generating ads rather than shooting one with a video studio; it's so obviously helpless, desperate and obviously futile in the face of what's coming.
I mourn the future that seems plausible here but I also welcome it as inevitable. The technology is coming, and people are going to have to adapt one way or another.