If you haven't ever written a novel, or even a short story, you cannot possibly imagine how much of your own weird self ends up in it, and that is a huge part of what will make it interesting for people to read. You can also express ideas as subtext, through the application of technique and structure. I have never reached this level with any form of visual art but I imagine it's largely the same.
A prompt, or even a series of prompts, simply cannot encode such a rich payload. Another thing artists understand is that ideas are cheap and execution is everything; in practice, everything people are getting out of these AI tools is founded on a cheap idea and built from an averaging of everything the AI was trained on. There is nothing interesting in there, nothing unique, nothing more than superficially personal; just more of the most generic version of what you think you want. And I think a lot of people are finding that that isn't, in fact, what they want.
There is a literal cliche "my six year old could've done this" about how some of the techniques do not require the years of training they used to.
And a literal cliche response about how the eye and execution is the current determining factor: "but they didn't."