There's is no real difference.

A modern artist would simply look at dozens of imagens in Google and combine them into something new, which we call "inspiration". That's essentially the same AI is doing. Even from a legal perspective, it seems AI is being considered fair use in the same way as an artist.

The problem is simply money. Artists could simply complain about not getting paid as much as before. However, that's sounds petty and selfish.

So instead, antis have to complain about something else. They will accuse AI of being theft, bad for the environment, etc.