JazzG US government finances not being sustainable long term is something you'll need to substantiate. Generally public debt is not comparable at all to private debt, they're so fundamentally different they shouldn't even be called same name.
Economies have a public (govt), private (businesses and households) and a foreign sector, the sum of their balances always being zero. When the private sector is a net saver (i.e. saves more than it invests) which has been the case in most of the western world for decades then you need either the foreign sector to balance the books in your favour (i.e. get other countries to import more than you import from them, e.g. the German model) or you need the government to step in, otherwise your economy shrinks and nosedives.
What would be unsustainable long term is if governments followed your advice and stopped racking up deficits because that would mean there is no one to balance the private sector's lack of investment, the rest of the world literally can't do it for each other by definition so the only alternative to the govt doing it would be finding aliens willing to go in debt for us.