Let's have a look at Scandinavia or Germany. They have reasonably generous welfare systems, but they are means tested. So for the sake of argument, declare them to be 'truly livable'. Especially by global standards.
Now I claim, that you can get pretty much the same net payments (of means tested welfare - taxes) that these countries have today with a system of (UBI - taxes). Basically, at the moment both taxes and welfare are means tested; you could move to UBI by moving all the means testing from welfare to taxes.
Because net payments would be pretty much the same, all incentives would stay pretty much the same as today.
See also https://en.wikipedia.org/wiki/Negative_income_tax which is one way to implement something like a UBI.
Of course, if you want to go much beyond what Germany and Scandinavia are already paying, you'd need even higher taxes or a stranger economy.
Btw, per capita the US is one of the world leaders of social welfare spending. They spend more than France. (Mostly because while France spends a higher proportion of GDP, American GDP per capita is much higher.)