> The decision not to work and live off of UBI is only attractive to people who are currently working many hours and earning about the same as what UBI is offering

The evidence of people usually choosing to retire upon reaching the age they are able to receive much smaller stipends than their current earnings suggests otherwise. Many people value their free time highly, and a poverty wage to a single parent living in rented accommodation can be quite comfortable when doubled and applied to a homeowning couple with savings for rainy days.