If you're looking to avoid KYC Bisq is a good choice. The only issue you're likely to face with Bisq is that all trades must include BTC, so you'll have to trade your USDC for bitcoin, then sell the bitcoin for cash. In the US you can trade bitcoin for Zelle, which is fairly safe from charge-backs. Since Bisq requires trade deposits, it tends to deter scammers anyway, so the risk is pretty minor. It can also facilitate face to face transactions that are pretty safe, again due to the way bisq sends the funds to a 2 of 2 multi-sig wallet. You can also facilitate selling bitcoin for US Postal Money Orders or Cash by Mail.
How will he protect himself from an unscrupulous postman who steals that $5,000?