Why do humans keep loaning us money?

Us is the USA.

Obviously, to me, it is because they can make money, and have trust and faith in the US federal government to pay its bills,to include repaying borrowed principal and the interest on the borrowing.

This also assumes we citizens will work to pay our federal taxes, and agree to these payments authorized by our elected federal politicians, and their appointed minions. And we Americans seem to keep electing people that do this to us. Is this simple enough?

The catch is also obvious to me.

If we can't or won't pay our bills, which will affect our children, then others, not politicians, will be in charge. Maybe it will just be that the loaners can't make money on a loan?

In this is the dilemma about what to do.

Hopefully we can vote, otherwise things like revolt come up.

In the end, we the people are in charge, one way or the other.