I think the difference in artistic expression between modern humans and humans in the past comes down to the material available (like the actual material to draw with).

That is definitely a difference, but even that is a kind of information shared between people, and information itself is what gives everyone something to build on. That gives them a basis on which to advance understanding, instead of wasting time coming up with the same things themselves every time.

Humans can draw without seeing any image ever. Blind people can create art and draw things because we have a different understanding of the world around us than AI has. No human artist needs to look at a thousand or even at 1 picture of a banana to draw one.

Humans don't need representations of things in images because they have the opportunity to interact with the genuine article, and in situations when that is impractical, they can still fall back on images to learn. Someone without sight from birth can't create art the same way a sighted person can.

The way AI sees and “understands” the world and how it generates an image is fundamentally different from how the human brain conveys the object banana into an image of a banana.

That's the beauty of it all, despite that, these models can still output bananas.