Would you like a banking service that delivers cash to your apartment?

No.

I can’t use cash for online payments, only in person. So, I would already be out and about. There are ATMs all around. So a cash delivery service would be useless.

No. You’d have to pay a fee to get the $20, and it wouldn’t be worth a fee just to get cash.

If I’m out and I don’t have cash, I use credit cards. When I run low on cash, I go to the ATM and pick some up.

No

No, I almost exclusively use my debit card.

N O !

Why pay ten dollars to get twenty delivered ?

You would have to sign for too.

No thanks. I would not want to advertise that I likely just received cash money.

Imagine the amount of theft that would be going on.
I also assume they would be wearing uniforms, so would-be-robbers could easily identify them and, well, rob them. And as a niche service, they would not be willing to pay for the kind of security that banks do.