But people who want serious development in art use physical models and highly-realistic photographs to direct and practice their skills.
So-called "AIs" don't develop their technical generation skills by being shown reality as directly as possible. They're expected to imitate, not create.
Photographs are used to train nets to parse photographic images. Art is used to train nets to produce decoration.
When humans train in an craft like drawing, if they're interested in one particular variety (like comics) they might use samples of comic art as training tools.
Well, it's Juneteenth, and I have one objection about the holiday:
The name is awful. It neither expresses what it's about, nor when. Unless possibly it's interpreted as indicating the period between June 13th and June 19th... which it does not.
They could have done better.