Won't somebody think of the children?!
Imagine this: It's 17,000 years ago. Your family is staying in a cave because the weather is terrible. You have children. They are driving you nuts. How do you entertain them? You draw stories on the wall with a burnt stick. They are delighted. You embellish with ground up rocks, berries, whatever. You've got nothing but time and what's available nearby. You're stuck in that cave for the entire winter, or multiple storms over the years, or maybe you just stay there because it's comfortable and there's water and plenty to eat nearby.
I think that's where the ancient paintings in France came from. I don't think they were talking about hunts, hunter-to-hunter, or worshipping anything.
I think they were amusing their kids.