Currently, in the US the top 10% of earners are responsible for approximately half of all consumer spending. If AI causes this trend to continue and accelerate, I expect that we'd see similar dollar amounts of consumer spending, but it would be concentrated mainly in the people whose income comes from capital investments rather than from working for wages. Basically you'd see a situation like this: https://www.youtube.com/watch?v=snsXD6FwLYc