Sorry, but this is mortally flawed goldbug logic.
You need to replace "faith" with "200 years proven track record and the economic self-interest of 300 million citizens, backed up with an army".
If the US lost: "200 years proven track record and the economic self-interest of 300 million citizens, backed up with an army", then maybe, but not even you are arguing that, because it's
obvious nonsense.
Using the opaque and ultimately meaningless word of "faith" led you to this flawed path of logic.
Btw., the following argument is flawed in the specifics as well and shows a lack of understanding of how financial systems and treasury bonds work in particular:
That's a very naive understanding of how treasuries work. If there are more sellers of treasury bonds than buyers, and the Fed doesn't like the spiking yields, they'll step in and buy them. There's no danger whatsoever of bonds "collapsing", because the Fed has unlimited authority to acquire them - and has done so in the past.
The "masses" cannot "cash in" treasuries "one day", they have fixed maturities. They can sell them, to the Fed if there are no buyers. I.e. there's no possibility of a bank run on the Fed.
Your argument goes downhill from there I'm afraid.