There’s two different types of driver here. the non-HGV van driver who delivers things like bread and crisps usually does stock the shelves, I think some get a commission on how many is sold. The HGV driver like Pepsi/Coke cola and the milk guy who deliver trailer loads unload their palletized product in the back room of the store then hammer down.
The milk driver puts the milk in the cooler and the store workers take care of it. Pepsi/Coke cola employ what they call merchandisers to go to the stores and put the drinks on the shelves as needed. Any other merchandise delivered to the store by a HGV is unloaded by the store workers.
At least that’s the way it is at the stores I used to deliver to over here.