The US has had a long way to fall. In a wealthy economy can suffer a great deal of public finance abuse: there are many wells that need to be dried up. The progression of the US toward that goal includes, most recently: progressively shifting to ever shorter term notes to finance deficits and large scale monetizing of deficits, such as during the Great Recession and COVID.

We'll get there. You'll know it's over when you get "bailed in" and the treasury starting minting trillion dollar coins.

Public debt is more like a brake that gets worse and worse really slowly over time.

And then it suddenly explodes - more and more of the budget goes to interest payments instead of procurement.

At one point the government has to borrow to make payments on the debt, and then you’ve got a very bad spiral.