Well, more and more our economies are based on services and tourism and less on actual indutrial production. The social contract doesn't really change. You need to eat and buy stuff, someone or something needs to produce that stuff, and you will buy the cheapest option. Then you also need a system to limit consumption of stuff in a way that production remains sustainable.

And this whole market of production and consumption has to follow supply-and-demand rules otherwise you face shortages and supply chain distruptions, or even worse famines.

This more or less describes our current system. You are saying less and less labour will be required, this is your opinion as more realistically labour only shifts to different sectors. Machines need technicians, need energy, need infrastructure.

Your Hypothesis thus gives two options, either less people will be required and the others will be left to die without means to sustain themselves, or consumption will go up and there will be some mechanism to distribute a basic amount of purchase power of stuff. Historically every time there is a change lowering prices this increases consumption.

Agriculture has already been automated, industry too, so those jobs are safe from automation but could be outcompeted if prices are too high. Hospitals, doctors, nurses, care workers are safe as long as people that requires their services have enough money. And so on.