without being too romantic, many of the human parts in this equation may also turn out to be autoregressive and possible to automate
Purpose - a bot could probably coordinate people around a mission more persistently than a human. Take online activism. A bot could post, gather and prompt people around a purpose. I expect they probably already do (see Geese botgate or fake political bots etc).
However one reason we attribute purpose to art is that we see ourselves in artists. We take cues from them to alter the course of our lives and give that journey meaning.
That would be tough to automate, and is applicable whether those artists use AI in their process or not.
Arguably in a world full of AI we might find more meaning in learning how other humans use AI, and less meaning in denying it.