If you’re genuinely curious, a lot of it has to do with traffic management. I will blindly assume that you live near a large city in north america.

Trucks are big and cumbersome, especially semis. They’re fine ok the highway, but on city roads around busy places like grocery stores they’re like one man traffic jams.

Your typical American grocery store moves literal tons of product every single day, very little of which is produced locally. They require constant, daily replenishing, and it has to be done without disrupting the flow of shoppers and surrounding traffic.

The solution is to start your night at a store or distribution center in a major city. Pick up your trailer of paper products or whatever, make your first stop in town, then hit the highway. Stop at towns and cities along the way, dropping off a pallet or two at each until you reach your final stop in another major city where you swap trailers and take a nap before doing it all again. Many grocery stores employ a small team of (frequently underpaid) workers to process all this at odd hours in the night.

Supply chain is 24/7