There are many ethical concerns with using AI art, I think that if you're interested in knowing more there is a significant amount of information about that out there since it's a very hot-button topic at the moment. Just searching for "ethics of AI art" for example, would lead to a lot different resources from articles to reddit posts, etc.
I am no expert on the subject, but generally, how I sum up the main problem, is that there is no public-use AI that I know of that has been built on art that they sourced ethically. In many cases it was taken without permission, and in the cases where they do claim to have permission, it seems like that permission was gathered retroactively (because AI is a relatively recent phenomenon)
AI needs a massive database of images to begin to learn the patterns of how to create more images, and in this situation that core seems to be built without properly gathering the rights to do so for essentially every mainstream AI image generator.