They are common for delivery of items for building and places that don’t have loading docks. Literally all over the USA. About 4 major manufactures.
Yes, we have those. I most often see them on trucks delivering lumber and building supplies (plywood sheets, drywall sheets, etc.)
Industrial gasses are usually delivered by smaller regional trucks here, and probably have a liftgate if they aren't going to a dock.
Interesting. Here, I see them mostly on trucks that deliver beverages.
Loading docks are common here. I'd guess the trucks-with-forklift are going to job sites where there isn't any way to unload materials.
Makes sense. Beverages are often delivered to bars and restaurants.
The Zyklon B bottles for the outfit in in pic related doesn't have a loading dock. They have fork lifts but sometimes the delivery is made before work there starts very early in the morning. This way the trucker can unload and doesn't have to wait for anyone to be there.
Yes, they typically were on the sod trucks. They're cool little machines.