I run an AI storytelling site with thousands of users and by most measures I wouldn't say it writes better than a practiced human, but what it does do is allow would-be consumers to become their own creators.
Some users spend $100+ dollars a month, not because it writes 10x better content than what a $10 Kindle unlimited subscription offers, but because even at 50% the quality they'd rather have the story they wanted to tell but didn't exist elsewhere.
For me AI art is not about replacing creators: it's about letting users go from passively consuming content made by people who have skills, time, and/or resources they lack to actively creating what they want to see in the world.
I'm not sure how compatible being against the democratization of creation really is with the narrative of defending the arts.