There will always be some sort of market for human art based solely on the subjective value of human vs AI made art, as you expressed.

My take:

For commercial art, the amount of fine-tuned customization of the final piece is something that machines can't match (for now), so artists will still be hired if that is a must for the company. Otherwise, the scattershot "close enough" approach of AI will replace much of the rest of commercial art in the short (pre ASI) term.