Thanks. I do understand the value in holding debt, to my engineering brain it's analogous to a heat sink - without it, energy (money) has impetus to flow. I guess I don't have a good sense for what "the right" amount of debt is for a country, so to your point, I don't really have solid reason to assume we should even care about buying down our debt.

I think the root of my confusion was clarified by the other reply above - it's not that the US just has a stash of excess capital coming in and UBI is a way to spend it, but rather UBI is a way for a government to step in, and force it's ultra-rich citizens to put their money back into the economic engine at the base level... like an artificial mechanism to account for some percieved flaw in the natural capitalistic process.