Sounds like a small market and not a very good business.
The profitability is the question here though - the market clearly wants this service, but at what price? To make it so that it is profitable for the business while also offering a fair wage to the workers will probably increase prices to the point where it is no longer desirable from users.
If a supermarket can be profitable while it employs people to stack the shelves, man the checkouts etc., why can't you just move those people out into the neighborhood as delivery people?
Hannaford's pickup service is $5--which COVID aside seems like it would be mostly useful only in specific cases.