The data on UBI isn't out there, but it is notable that countries with similar tax rates to the US manage to have universal healthcare and more expansive safety nets. Some examples: New Zealand (tax rate ~30% less than the US), Korea, Switzerland, Australia, UK, Japan, Netherlands, Norway.

Americans really should be asking why we're paying a significantly higher tax burden than New Zealand and not getting similar services as part of the bargain.

Put another way: the US is incredibly rich compared to other countries. Our poorest states have higher GDP per capita than most rich countries. And our taxes are not particularly low. Our social issues are 100% about how we choose to allocate our shared resources. The good thing is we can always choose to make different choices.

Switzerland has mandatory healthcare insurance and subsidies for low income earners. The insurance is provided by private companies. It's not really universal healthcare system like in most EU countries.

Private insurance can work out fine if regulated well. In USA you have regulatory capture that makes services expensive. Impossible barriers to entry coupled with terrible regulation on price transparency and a lot of cartel like behavior.