Does it harm existing creators? Probably, in the sense that it enables new entrants to the market and creates more competition but that should be acceptable. We live in a market society (since every other economic form has been a failure) and we need to acknowledge that sometimes that means people get their livelihoods destroyed. If we start picking and choosing, who deserves to keep their livelihoods we fall into political traps which aren’t ideal (why do we care about artists but not coal miners?).
Another point I want to get at here is that in a world of abundant art, I would expect art to be more compelling. I don’t know about you but one thing I find a bit frustrating about Anglophone art is that too often it follows the same tropes and happens in the same locations. A world of abundant art can solve that.