We truly are in the second age of the robber barons.
But training automated systems on the works of human artists in order to create dirt cheap imitations at scale in their (formerly) distinctive style could certainly make it harder for active artists to find paid commissions.
Flooding the world with inferior imitations seems like it might have some negative consequences as well.
"I am shocked, shocked, to find that copyright infringement is going on in here."
"Your LLM, sir."
"(Oh, thank you very much.)"
Next time please pay me $5 when you sell my data.