Who will hire them? Everything is being done by the machines, the companies can't fire the machines, and there's no hungry market to sell the machines into because everyone has machines.

That is the difference between humans and machines: *You can't fire machines, only sell them.* They are mechanical slaves. You own the machines, so you are stuck with them (and their costs, which are high and never-ending), unless you can find a buyer, or you go bankrupt and write them off. That is why mechanisation and automation are a one-way street, for any company. It works or you are gone.