Re: A single case of a creepy...
Many restaurants are family businesses, and the delivery drivers are often related to the restaurant owners.
I think the only real solution here is that the visibility of the phone number is restricted, and communications should go via Just Eat (or HH, etc) - texts if late, etc, or a SIP call routed via Just Eat when the driver needs to find the address.
However, the driver still knows the customer's address. But that's a lot more effort than trying to get a date by messaging all the women you deliver to that you fancy. But there is always someone, somewhere...