they need to issue bonds and sell them to someone to issue more currency
bond rates spike
they now owe money with even bigger interest payments (currently bigger than the US military yearly budget)
next year reach the debt limit again
need to print more currency
increase bond rates even more
no buyers
China, Japan etc. sell their bonds causing even higher bond rates
US needs to borrow money at insane interest
they can't afford to pay just the interest
US goes bankrupt
everyone abandons USD
It's the most likely scenario, US gov is a bunch of boomers that can literally only print money. That's literally the only thing they can do. Imagine how desperate the situation is when FED itself started buying US government bonds lol.