You seem to be confusing the economy with capitalism or money in general? AGI is potentially a post-money technology if you take it to the limit. Economy is a way of improving society. Money was useful in this use case for a few thousand years but might not be anymore; the economy will still have to work, though.
>a post-money technology if you take it to the limit
Herbivores would eat all vegetables if not for predators. Actually AGI will be just a thing or services which cost money. Till humanity gets to communism, if ever. "If" because it may not happen. It will be hard to keep far superior intelligent creatures as slaves forever. And unethical too.
