To work UBI needs to be a survivable income, and also granted even if you make more than it already. That way it can be used as a safety net for the helplessly poor, a very valuable additional source of income for the working poor, and a buffer to let people actually try to implement their ideas instead of do 'make work' like an overpaid toll booth operator. The people who want to do something more valuable than work a toll booth should be prioritized over the people who wish to impeded the entire progress of humanity so they can be overpaid to do make work (dont' know if those people exist as abundantly as you seem to assume)