A very big part of art (probably the biggest part) is the meaning behind it. AIs have no internal "experience" or novel ideas so the art is ultimately meaningless, or only as meaningful as the idea behind the prompt the person put into it. This is why you can have an incredibly slick, high budget movie that is universally considered bad because it's soulless. If AIs become "conscious" or something and we actually have an interest in how they see the world I think their art could be interesting. Even without the consciousness I think that we can have interesting "art" that comes out of them based on how they see the world, which brings to mind things like the old Google AI Image generator hallucination/dream images from a few years back.