Yeah, parent comment is scary - glad you called it out. Although I don't have an economics degree, I do a lot of bond future trading on the side and am in fairly good tune with the bond market/how their yields work. The effect on the bond yields alone if the US defaulted would be disastrous.
“I have a few degrees in economics” is an appeal to authority, and a laughable one at that. Economists are historians that tricked themselves into thinking that overfitted models of the past predict the future.
2008 was obvious in retrospect but the government that is full of economists did nothing to stop it. They lauded things like Clinton getting the govt to back housing loans because there is “a school” of economics that claims that’s better than the “other school” of economics that is focused on the moral hazard.