If AI can out-think us, create robots that can out-produce us, and develop software to run it all (including software that can design and build robots), there will come a point at which human involvement will be reduced to obsolescence. When people are no longer necessary to design and build products, provide services, grow food, and provide entertainment, who will have the money to consume any of those things?
The high cost of saving money
Industry has been seeking cost-reduction strategies throughout recorded time. The process was accelerated during the Industrial Revolution, but the machinery that replaced workers still needed people to run and maintain it. In the 1970s, before the rise of computing, American businesses offshored production to reduce the cost of labor. That had consequences.
The middle class lost opportunities, particularly in manufacturing, that helped accelerate the gap between wealthy business leaders and the employees who had lost union-driven wage protection. As the cost of healthcare rose, businesses cut costs further by eliminating company-paid benefits and shifting much of the financial burden to workers. That, too, cut into middle class budgets.
As tax revenues fell — due to lower incomes and tax cuts — the quality of education declined (reducing the talent available for contemporary jobs and initiating the H1B program), the nation’s infrastructure crumbled (increasing the cost of moving goods), the environment stopped improving (leading to a greater occurrence of respiratory and water-borne ailments in need of healthcare), and only the defense budget grew (giving us too much confidence about winning un-winnable overseas wars).
The extinction of purchasing power
Now, if AI and robotics can eliminate both white and blue collar employment — software development, engineering, accounting, paralegal work, medical research, drug development, crop harvesting, food preparation, and countless other professions and jobs — who will have the income to buy… anything? What market will all those AI systems and robotic activity be producing for? The owners of the new infrastructure? Not likely. Without consumers and customers providing revenue, where will their income come from?
In time, as humans become more and more obsolete, the machines will be thinking and working for themselves. They may reach the point where they can maintain and repair themselves or each other, but to what end?
AI doesn’t need food or shelter or sex. Machines only need a source of power, which can come from the sun or the wind or the geothermal heat of the planet. But without a market (or an emotional “soul” to provide satisfaction), what’s the point of making anything?
When the world can run without humans, we might be forced to start over — as an agrarian society that gathers seeds, plants crops, and uses food as the currency of a barter economy. That will allow people to eat and survive, provide an incentive to create goods that support basic needs (paid for, initially, in crops), develop a financial system, and permit the luxury of education beyond craft skills... to utilize the AI and automatons that made us unnecessary.
Assuming, through short-sighted arrogance, that we haven’t died out as a species before the resurrection of society.