The skills required to be able to compete and build upon AI generated art is going to be beyond most people born into working class backgrounds. The number of jobs this will eliminate will ensure only the top performing artists (nepotism and networking notwithstanding) will be able to find and retain stable employment.

A shrinking field generally means it will be progressively whittled down to only elites and the children of elites will be able to significantly participate and contribute.

It's the floor falling out from the supermajority of junior and lower performing workers here, combined with capital being able to literally absorb workers' unique abilities into dead capital and render their future labor worthless on the market.

This kind of automation has never been seen before, being able to render even products of human self-expression, solidarity and compassion infinitely replicable and therefore worthless and not worthy of compensation in market terms is horrific when as you mentioned proles are already mostly locked out of cultural means of production.

The shared interests of workers still leave their marks on mass culture, even sometimes explicitly with movies like Parasite etc, I just can't imagine the long term implications this kind of Pandora's box (total death of creative fields as a livable career for proles) will have for cultural reproduction decades down the line especially when considering how evil Americans already are, and how evil American culture already is. It's a tightening of contradictions.

It's also really not great that now workers lose almost all their leverage in these fields and quite literally can no longer withhold their labor.