I don't know how well this actually translates to AI, though. We all understand that AI art has a pretty low quality, but sometimes low quality is enough. If I want an image for my D&D character that only I and my DM will likely ever see, I am fine with a 7 cent AI-generated image, but I'm not willing to pay 150$ for an artist to do it - not that I don't value their time, I just don't value the image that much. Before AI this was the same, I'd just have used an image from Pinterest and thought "Well, this isn't exactly a good match, but I can't find anything better".
But I assume real illustrators do things like illustrations for children's books? I'd like to believe that those are still done by actual people, not AI.