[0]Instead, I think a constellation of smaller, targeted programs (think best-of-breed) might be more effective and provide a more robust effect: If a society provides universal healthcare, comprehensive unemployment benefits that don't have absurdly low caps, housing & food subsidies for those close to the poverty level, comprehensive disability benefits, and probably a few other things I'm missing, then the need for a "universal" UBI is diminished: That too can be targeted towards people not otherwise covered by the above. The advantage is that each program can be highly tailored to the specific needs & nuances of those seeking that specific benefit, rather than just throwing a larger block of money at people.
[0]Note: I'm not particularly attached to this idea. I think is has merit, but my goal is to start a conversation about the idea, sort of pressure-test it, not proclaim it as the way to do things.