You assume that the people who are at the top of the organizations generating said wealth will have any incentive to do that. Look around the world at the petro states for examples of a highly capital intensive industry generating money that subsidizes the rest of the economy.
1. AI seems different here, American AI companies doing better seems to result in the rest of the American economy doing better as intelligence is generally productivity increasing. Plus it's not bound by physical scarcity as oil. It feels more like cloud computing or electricity
2. Even if we were to assume an analogy to a petro state, it seems like we as a society can decide if we go the route of Norway or Venezuela
If you think that people won't have work and therefore no money to buy anything, there will be no wealth- not for the people and not for the riches. The value of Google or Tesla go to zero without masses of people paying for their products.