How? A driver-less truck pulls up to the front of a corner store. Then what? Someone still has to take the (correct) product from the truck, load it on a hand cart, take it into each shop and put it on the shelves. Normally this is the driver of the truck, but if you automate him away then every shop-keep need a guy hanging around to unload the auto-delivery trucks all day or take time away from serving customers to do it themselves.
That is not a clear net win to me. It is a physical manifestation of automated phone support. Cheaper to implement by the company but more time consuming and less useful for the users and less efficient overall...
Other items were ordered from a wholesale distributer. Those were delivered by truck to the loading dock in cardboard boxes. We moved those into the store, unpacked the boxes, and filled the shelves.
Beer and such was put into the walk-in by the driver, and we stocked the coolers as needed.
It will be a long time before the local ice distributer goes automatic (for economic reasons it makes sense to make and distribute ice very locally). But wholesale distributers? I can see a truck with a lift gate and some kind of robot to automatically unload the truck. We always had to be there to receive anyway, except it was a human with a dolly moving the boxes into the bay.
The manufacturer/distributor sets the price and the grocer could care less whether any sells at all, as long as they find a way to keep getting foot traffic.