There is also the philosophical argument about what is creativity other just mixing already seen inputs, and Hume and Kant and bla bla bla. Imho creativity is precisely this, combining things that exist in novel ways, because ex nihilo nihil fit. After all, the human illustrator has learned by copying others too. In the end I do not see such a difference.
@remenca You're missing the point. You can use CC0 data, but you don't because it's just not enough training data.
And I don't care about what you think about creativity. That wasn't the argument in the first place. This is about the human cost, the human effort. No matter how "hard" it is to train your model with unethically obtained data. YOU are not the one being creative here. And it shows.