Besides massive and growing pollution:

It inevitably smashes people’s motivation for creativity down, as no public cares or is even able to see the difference… Or, rather even because actual human artistic or craftsmanship efforts are drowned under kilotons of useless generated crap.

But:

Pollution is the massively serious sideeffect of AI (asshole idiot) Smash human creativity down is the massively serious desired effect of AI (asshole idiot)

It’s humans (probably uncreative humans) who create, promote and defend AI. Probably greedy humans who have financial interests doing so. Of course, one of their first plans is probably to harvest millions of music royalties off streaming platforms in lieu of creator artists by bombing said platforms with thousand uploads everyday.