This is from chapter 7 of Scott McCloud's "Understanding Comics." (Check out his site here)
I think it's pretty self-explanatory on its own, but my thoughts are basically that AI-generated art really only falls into category 6 (maybe 5) of the different "layers" of art. It's pure surface, with a little bit of understanding of the structures of things (even if it's only following diffusion patterns and doesn't know what those "things" are), but I have seen no evidence to suggest that AI can do any of the other things there as it stands.
Let's take something like Superman as an example. On the surface, it seems like an AI could have easily replicated it. The "strong man" heroic archetype is extremely common in fiction, back as far as Heracles and Gilgamesh. There's plenty of other sci-fi around at the time, so aliens aren't that far-fetched. The Scarlet Pimpernel and Zorro popularized heroes with a false identity. And even the art style is fairly common for the time. So is Superman all just ideas lifted from other people? Could an AI do that?
Let's look at it from another angle. Superman was created during a time where antisemitism was at its peak. There were also the ideas of eugenics and the "Übermensch" floating around.
So, two Jewish men with prior experience in the sci-fi genre did this: they created a "superman", an ultimate being, who hailed from another planet in a story much akin to that of Moses, in order to fight for the common man. In his first appearance, this Superman collected the evidence necessary to convince a judge to overturn a faulty ruling (saving an innocent woman from execution). He kicked the shit out of a wife-beater. He saves a journalist (Lois) from getting kidnapped by some entitled thugs. He beats up some lobbyists working with a corrupt senator to pass a bill prolonging a war in South America, uncovering a plot by a munitions magnate in the next issue. Essentially, Superman is fighting for the underdog in these few issues, moreso than acting as an agent of law and order.
Basically, it touches upon a metric crap ton of hot-button issues for the time. I can't imagine an AI being able to come up with (or even understand) the irony of using a "superman" (uber-man) to fight for the downtrodden in a time like that. Frankly, it's rare to see superhero writers do that sort of thing today. After all, Siegel and Shuster trailblazed into a completely new genre of stories. The "surface" may pale in comparison to comics today, but the ideas underneath Superman are rock solid.