This is a bad faith reading. The argument isn’t that “someone else did it first” - the argument is that the concern over copyright is suspiciously sudden. No one has gotten mad about danbooru - or Reddit, or Facebook, or any of the other billions of sites that use content created by others to draw users and make a profit from ad revenue. Why are people mad about some neckbeard’s $3/month patreon based on an unoriginal art style, but not about Facebook (etc) destroying the entire thing that used to be called journalism? Danbooru literally stole the work, why is no one mad about that? Why are they only mad when someone figuratively steals the work?

AI art has a similar potential to do to set what Facebook did to journalism - I just wrote a long post about it in another reply in this thread so I won’t repeat it all here - but, wealthy corporations will be able to use AI art to destroy the career of being an artist. That’s what’s dangerous about AI.