I think most trades would be better served by a van rather than a pickup truck. Ingress and egress is much easier. It is also easier to load and drive due to lower center of gravity. Expensive tools are out of the elements and generally safer (and so less risk of tools and material making their way onto the highway). Plus, better drag coefficient and so better efficiency. Finally, a roof rack allows for those items you mentioned like sheetrock and plywood, ladders and pipes.
The biggest problem I see is most of these men have an ego that would never allow them to buy and drive a van.
All but one of the contractors I’ve had working on my house over the last few years used vans: holds more and your stuff doesn’t get rained on or stolen.
The one exception was the HVAC guy who had an old 90s-size pickup, which he liked due to the better mileage. He needed to fit bulky stuff, not massively heavy things.
The independent plumber I use when something goes wrong with the pipes drives a GMC Savana van. He's really good; close to retirement age and very methodical and thorough and his prices are reasonable. The electrician I use also drives some sort of van. I've had a few other contractors out for different projects around the house and I'm starting to notice a correlation: the ones in the giant lifted pickup trucks are unreliable and overpriced; the ones who drive vans are the best.
My electrical contractor relative just bought a Metris over a Maverick because of storage space and interior shelving. This is extremely common. People who work outdoors usually prefer pickups because they have larger equipment and materials, and more varied terrain
Yup, my dad worked as an electrician with an ISP for some years, and he had a van. Think it was a Ford Transit that was fitted with drawers and cabinets for tools and parts. It was literally a workshop on wheels. All the tools and parts you could imaginable need.
Something like a Ram ProMaster van is rated for 6-7000 lbs towing capacity, which may not sound like much compared to pickups that primarily compete on the basis of that particular specification, but it's still definitely enough to be useful.