Your entire argument hinges on being able to tell the extent to which generative AI was used in the creation of any given piece of art, which capability you will not have. You therefore fall into the category the commenter mentioned in that your perception of the value of a piece of art can be heavily influenced by someone convincing you it was AI generated, regardless of the facts.
You don't get it.
Jut recently, there was a thread discussing Persepolis, a series of autobiographical graphic novels by Marjane Satrapi (recently deceased) that depict her childhood and early adult years in Iran and Austria during and after the Islamic Revolution. People remarked it was deeply moving.
Part of what makes it deeply moving is the actuality of it. This is a human story based on actual lived experiences. How does an AI produce this?? If it came out later that it was written by an AI (assume for the purpose of argument that we had AI when it was written), then of course m=it's impact would be different.
If a seemingly powerful piece of non-fiction is later exposed as fiction, and AI written fiction at that, won't that change your perception of it? Or if a nice anecdote someone likes to tell is exposed as made up, I would hope that matters.