I may be in the minority here when I say I don't see the problem. AI trained on millions of publicly available images used to speed up the concept stage of development seems like fair use to me. Like the developer says, commercial artists have always used other folks work to speed up their development, that sounds more problematic to me than drawing inspiration from a huge dataset.
"Fair use" has a specific meaning in copyright law. If something replaces the need for something else in the market, it's almost certainly not fair use. Generative AI replaced the need to hire an original artist.
Copyright can be violated even if your output does not contain a copy.
For example, if I burn a copy of your Disney DVD, watch it, and then write a review, then I've violated copyright. The review doesn't violate copyright, but the DVD I burned does. Even if I throw away my DVD after publishing my review.
All the major AIs were trained with images that were downloaded from the web. When you download something from the web, you do not have an unlimited license to do what you want with your download. You may have a right to view it, but not use it for commercial purposes such as AI training. And if you use that image for AI training without permission, then you've violated copyright. Even if you delete the image after you're done training your AI.
The SCOTUS ruled that VHS could legally be used to time-shift TV broadcasts, ie record a program in order to personally watch later. If you have permission to watch a TV program, then watching it at a different time has no economic impact and is fair use. Making a copy of someone else's DVD is still illegal. So is giving your VHS tape to someone else. They are not fair use.
It is illegal to download copyright protected works. That applies to the person who receives the download, even if lawsuits tend to target those who share the file.
It's true the review itself doesn't violate copyright, but my actions prior to the review (copying someone else's DVD) did. It's no different than sneaking into a movie theater in order to write the review. Focusing on the review misses the point
Any copyright protected work you gather from the Internet has a limited license. That license generally allows private non-commercial use, so most people are not in trouble.
There was actually a lawsuit by Facebook against a company that was using a web scraper to gather data about Facebook users to build advertising trackers. The judge noted that if the web scraper was downloading user photographs and text posts then it was very likely infringing IP (but not Facebook's IP, because the rights still belonged to the users).