Full attestation doesn't guarantee stable 1-to-1 valuation, even with all of those things USDC isn't equivalent to 1USD and treating it as if it were carries risk.
Definitely,but the Us dollar also carries risk so really there are no risk free assets.
I mean, in the absolute sense, sure, but the "risk" carried by USD is a categorically different, exponentially smaller thing than the "risk" associated with any stable coin. They're not really comparable.