> I don’t understand why there aren’t ghost groceries, similar to ghost kitchens or warehouses.
There are. FreshDirect has a state-of-the-art facility in the Bronx, and I'm sure Amazon has several ghost groceries also -- e.g. they just bought two Fairways locations.
Check out this video of the FreshDirect facility, it's actually pretty amazing: https://www.youtube.com/watch?v=fnIrwrCq_4Q