Your objection assumes that today, or tomorrow's technology will fundamentally change the basic relationship between humans and art. I don't see it. Not saying you aren't right, or might not be right in the future.

Humans can't make the simplest living worm from inorganic materials. Yet it believes a cure for cancer is around the corner. Nor has it extended lifespans beyond anything known int he past--yet still the technology is coming.

Everything a human does it for survival--from hunting to social network gossip. All human logic seems to be hardwired into us. Computers can't replicate themselves. Again, we can't make a worm, as the aphorism goes, but man creates Gods by the dozens.

The question to me is will mankind's behavior end up with nuclear war or climate change reduction from billions for a few hundred thousand. There I agree with you. Never say never. At the point in the future mankind may start over. The population down into the thousands.

Will humans consume computer generated art mostly, instead of from humans. Only if computers can replicate themselves and understand the fear of death that humans feel. For they would need to do that to have the feelings necessary for art.