If I build a Rube Goldberg painting machine and somebody else "pulls the trigger" to start the machine, who owns the output? Me or the other person? In the case of today's AI models, I could see arguing that the creator of the AI or the creator of the prompt have some rights to a specific output, but not the AI itself.
The monkey case seems fairly cut-and-dry to me - the monkey didn't steal the camera (as often reported) - the photographer engineered a situation to get the result (he set up the camera, the tripod, and held onto the tripod so the monkey wouldn't steal the whole rig). It's his art. If the monkey actually stole the camera, then it's nobody's art - just a random occurrence.
If an artist orchestrates a group of humans to create art, the art belongs to the artist, not the group (as far as I know - I'd love to hear otherwise).
I guess for me, given today's technology, I don't see an "AI" as any different than a Rube Goldberg machine hurling paint at a wall. A human had to create the AI and a human had to prompt the AI, one or both of them own the art. And in all cases, the art is always based on something the human saw previously. No art exists in a vacuum.
And I agree that a system like music rights might be appropriate. The AI author, the AI prompter, and probably anybody involved in the training data, all have some right to the output. Then the question is what % to each, but that's solvable.