> Once AI takes everything it can take, what is left for us?

This is a good question, but is perhaps too abstract to address well. I think a better question for right now is:

Once AI generates all the wealth it can generate, who benefits from that wealth?

If the answer is a small number of humans, that is probably a dystopia worth resisting.

If the answer is some number of AI agents, but no humans at all, that is probably also a dystopia worth resisting.

I think the only good outcome is one in which humanity benefits on the whole. If that means that we have to become a post-capitalist society in order to share in the wealth, so be it.