You see, capitalism is a paperclip maximizer but has no builtin paperclip model to produce. It is still made of people, and gets it's goal from those people all the time. If there's no goal given, it simply fails (economists call the milder versions of that failure mode by "deflationary depression").
Also, unemployed people are not completely powerless against capital. At least not now. Even if the people are completely outcompeted, even if the powerful few have an army of robot actuators, people are still resourceful and not powerless. The really scary scenarios are those where the powerful few owns an army of superhuman brains.
