But yes - this is why banks want to prevent stablecoin issuers from being allowed to grant rewards
I think you're basically correct here. I think the fear of the banks - and why they are insistent on prohibiting stablecoins from generating yield/interest (via the GENIUS act) - is that that doesn't stay true in the long-term, as stablecoins ascend as a cross-border payment/storage rail.
>Does USDC pay interest to the holder or do I have to make a USDC deposit at Coinbase in order to get paid interest?
I believe USDC from Coinbase is framed as "reward", and is downstream of an agreement Coinbase has with Circle to get that "reward" from Circle for all USDC deposits it holds on platform. Other "rates" you can get on centralized stablecoins tend to be similar AFAICT.
USDC should be paying more than T-bills to compensate for the counterparty risk.