The fee part is incorrect. Coinbase offers 1:1 exchanges of USD<>USDC with zero fee. On FTX it's the same, USDC and USD are treated 1:1 with no fee to convert. Deposit dollars, withdraw USDC or vice versa. Aside from these zero fee exchanges, many others have significantly lower fees for stablecoin<>fiat than they do for crypto<>fiat.