Not crazy given the incompetence in American political leadership.
BUT, if US treasuries default, your savings accounts, agency, municipal, state, international bonds, stocks - all will fail immediately.
Your literal checking account is backed by treasuries under the hood by the bank. Widespread bank runs will be likely. And even if you are at the front of the line in a run, you will not be able to withdraw $100k in actual dollar bills because banks don't have them in vaults like the old days.
maybe I am wrong but I view this as a very separate scenario from the US formally stating that it will default, which I agree would cause problems I'm in no way prepared for.
The current government is full of people who think it's clever, rather than short-sighted, to fuck people over.
It's not a joke that our credit ratings as a nation are slipping. It's real risk that those federal bonds may stop paying out.