Earlier quoted context omitted.
Wait, what? If people don’t need to work full time to nominally survive, that gives them much more leverage vs. employers. The BATNA during labor negotiations is now “live a spare lifestyle on basic income” vs. “let your whole family die starving in a gutter”.
He's speaking about leverage against the provider of UBI, who can simply lower or remove it.
For instance, “the ruling classes” could just as easily decide tomorrow to cut road maintenance, police response to violent crime, fire departments, emergency rooms, public schools, food stamps, public pension plans, access to parks, agricultural subsidies, grants for scientific research, government-backed loan programs, access to wifi spectrum, air pollution controls, carefully controlled monetary policy, bank deposit insurance, ....