Contractor here; vans are commonly used for trades that do lots of service work, and trucks for the ones who tend to do new installs/bigger jobs. You’ll see entire fleets of trucks and vans at the same plumbing company for example and see the divide. I’m so often putting gross or unwieldy things in the bed that a van doesn’t make sense, and there are plenty of other reasons a van might not be better. I’ve only ever seen locksmiths in vans for e.g., and never have seen a concrete finisher use anything other than a truck for a different example. It’s a tool at the end of the day and such a weird stance to ignore that certain jobs could be better suited to one over the other.
All of that aside, the “vans” I’m used to seeing that contractors use are essentially big enclosed trucks anyways so not sure why you’re calling one worse. Maybe it’s a regional thing in naming? My truck is smaller than most work vans I see around, so you’re saying I should be using the bigger vehicle that’s less suited to the tasks I need it for?