Uh, the key issue is that it's very unclear whether the results will hold at scale, since you're suggesting a modification to society. There's no (or very little) social component to the effectiveness of a vaccine or a new tool. Money is fundamentally a social construct and so what works in isolation or very small groups might not work the same way at large scale.

If a country with a population of around a million (or even as small as 100k) enacted UBI I would take those results to be representative of a societal change. So far I've only seen studies where a few people embedded in a larger society are given money, and that's not the same thing.

You have to remember that industrialized countries already have a systems where people get money for "nothing," but those quotes do a lot of psychological heavy lifting. Disability, unemployment, retirement, food stamps, etc. The difference being that it's not universal and each payout is either "earned," temporary, or a pity case. As such, the psychology behind that money just isn't the same.

I'm interested in UBI, I just want to see results that can actually be reasonably transferred to a population the size of my country (350 million) before I make hard statements about its effects.