If the US banking system starts failing, it absolutely should affect USD stable coins backed by exactly this banking system.
The USD is entirely unaffected. Some deposits at certain banks are affected for large (mostly professional) holders. Retail investors will be made whole (up to 250k), thanks to this banking regulation thingy you might have heard of.
USDC is meant to mirror the USD (sure, with its concomitant FX and inflation risk), but it is certainly not meant to introduce credit risk vis-à-vis some bank most people hadn't heard of last week.
The value of one USD stablecoin (measured e.g. in various commodities) might well go down, but the redeemability for one USD never should, regardless of the economic environment.
So, the "C" makes USD exposure available to anyone worldwide, assuming you have e.g. an Ethereum wallet.
Though that seems to have been the problem here.
The original idea with a 100% collaterilised peg was that the entire reserve would be cash. Somewhere along the way treasury bonds were considered cash equivalent. Which on the face of it seems sort of reasonable but clearly they do have a different risk and liquidity profile. This allows the centre consortium to earn a yield.
So I'm not sure I think a USDC is a dollar, but also I'm not sure it's particularly different to what banks do with deposits to earn a yield.
One difference is you can reinvest the same USDC to earn a yield while the underlying backing USD also earns centre a yield.
And if only we're true to the "original idea" (whatever that might be). As seen with lots of coins / exchanges it's been a front to do something else.
What is cash? Banknotes? You can't store 500 million pieces of $100 banknotes easily or safely.
Cash usually refers to deposits at accredited financial institutions like banks. Effectively this is an amount of money that the bank owes to Circle. The bank deposits money elsewhere, and the central place where all the money is distributed is the Federal Reserve Bank, the central bank of USA, that can never go bankrupt. OTOH, treasury bond is money that US Treasury owes to Circle, so they are not fundamentally different than cash, and in some cases it's even safer since US Treasury bonds are usually regarded risk-free.
Obviously people differ as to the utility of those applications but that's what the "C" gets you. You can do those things if you want to. Of course there's quite a lot you can do with actual dollars that you can't do with USDC so you give up a lot also.
[1] https://ethereum.org/en/developers/docs/standards/tokens/erc...
This is not a symptom of a stable banking system. It's a symptom of the banks having a disturbing amount of power over the government, which is not a good thing. They were able to conduct what is essentially fraud at a massive scale with impunity because they knew the gov would bail them out when shit hit the fan.
I really don't understand what's so "stable" about this.