Coinbase, considering they are the custodian of BlackRock and they have a debit card that allows you to spend BTC anywhere, and you earn 5% APY on USDC.
Most older people are invested in blackrock, and know it, so mentioning that they trust Coinbase with crypto assets may increase their trust in it as well.
The earning rate on USDC is crazy and blows any tradfi bank out of the water. I don’t hold any because I’m a bitcoin maxi but it’s still impressive.