> I don't think there are many proponents of that type of ubi.
Another good sign of a difficult policy to implement successfully/an idea that isn't ready for primetime. If everyone has different ideas of what the thing is, it's very hard to make good decisions, and easy for the "wrong" UBI to sneak in.
Other commenters have already made this point, but there are other ways to guarantee "subsistence". I think the hard to answer question is why are the targeted methods currently available not good enough? If we want to ensure people have food, then food subsidies/support make sense.
Also, if unemployment is the problem, fix that. If unemployment isn't the problem and people who are working aren't getting subsistence wages, fix that.
I think part of the problem is that no one wants to stick up and define what we think every human deserves and what we want society to provide. Does every human deserve housing? Access to green space? etc. Trying to clearly define this will lead to really interesting discussions that lay bare the disagreements core to society.
I think my early point still stands, UBI is not needed (we're making do without it now), and if it ever is needed, it's a sign of a lack of dynamism in the economy/ineffective wealth distribution mechanisms (basically, taxation).