Have you ever loaded drywall into a van? It is not fun. A truck bed is sized to load it perfectly. Strapping down lumber is also simpler. Lastly with nothing above the truck bed you can carry much taller things than in a van.
It isn’t the only way but yes a truck is very practical. That’s why they are used so much in the US. The difference between the US and the EU isn’t just arbitrary either. In the US gas (sorry, petrol) is a lot cheaper, roads are bigger, wider, longer, and sometimes you need to tow a large trailer. I tower a 3 ton excavator with my truck to build my home office.
Loading drywall into my minivan is a lot easier than a truck. I can fit whole sheets and close the back gate so I don't need to strap them down and they are protected from the elements.
I find it crazy that people would buy ton of stupid stuff from amazon, aliexpress or Shein but would not check the delivery option for stuff that is actually annoying to carry around yourself.
People who need a pickup bed for work usually buy those that come with the chassis of a commercial VAN which have a much bigger bed than you'd ever dream of on a Ford F series.
The rest are simply getting delivered or using trailers, either rented when used sporadically or bought. A trailer is usually at a more decent height and you don't have to carry the weight and have to manage a huge vehicle when you actually don't need all the space.