Which is exactly what happened for the other 1.4 billion jobs that don't exist anymore in the United States.
What you fear has been feared for a hundred and fifty years, since automation started to seriously replace workers. Instead of driving us to a dystopia, however, it's pushed us into a relative utopia.
What you're proposing isn't new. The implication you aren't addressing is that the trend of -new- jobs, previously not worth employing someone to do, but rising at the margins with increased specialization, arising as workers were freed from old ones will suddenly cease.
It's not exactly what has happened.
Machines used to compete on brute strength and endurance. Mankind always used to have advantages in intelligence, communication, sensation, and precision control. All of those are under attack in ways they have not before.
In short, people are rapidly losing a comparative advantage versus machines. The real problem comes when the opportunities for profit from using machines overcomes the opportunities for profit by employing people. The accelerating rates of improvement in technology will make that more and more the case.
As Multiheaded added, "Personal is Political" stuff like gender relations, etc also may belong here.