Society must produce at least to feed itself, and people working is the way we produce. No country in the world has fully automated its food supply, no one is even trying! and the US has outsourced a lot of its food supply to third world countries. That is why you think people need to work less and less every year, because the US imports more and more every year. The minute the US stops working is the minute the rest of the world stops sending in food.
We produce more per worker with every year as technology improves. It follows that we could do less work per person every year.
I'm talking about humanity as a whole, not the US in particular, so it doesn't really matter whether people in the US eat food that was grown in the US or elsewhere.
Demand is a no one-dimensional entity though unlike what you'll see in a macroeconomics report. The demand for smartphones in 1900 was precisely 0, for example. What happens is that our consumption will spread out and decrease in other areas, which puts some pressure on those industries to compete. Americans spend less and less on food now both because other things take up more of the monthly budget as well as cheap food options being available. Yet Belgians spend many times more / month on food and less on rent compared to Americans. Consumption also is dampened by taxation (pretty consistent in MMT and is probably closer to how things work under a reserve currency country).
Society must produce at least to feed itself, and people working is the way we produce. No country in the world has fully automated its food supply, no one is even trying! and the US has outsourced a lot of its food supply to third world countries. That is why you think people need to work less and less every year, because the US imports more and more every year. The minute the US stops working is the minute the rest of the world stops sending in food.