They also keep dirt and road dust off your tools and materials. Vans also conceal your cargo better than a bed which can prevent theft. Most vans are more fuel efficient than similar sized trucks. Vans are usually easier to drive and have better visibility. A big enough van can fit a small workshop in the back, that you can stand in and assemble parts.
Vans are the better work/trade vehicles compared to trucks for most applications and that is a hill I will die on.
I use a 4 door short bed truck, and here’s why. I need to pick up my kids half the days of the week. I don’t have a van anymore because I do demo work and I got tired of riding inside with the dust. I just build a wood rack if i need to haul more. I’d get a 4 door, long bed truck, which would be the best ever except it’s just too dang long to park. So when the kids aren’t around I fold up the rear seats and the tool boxes go in there. Is what it is. I long for the days when I drove a car with a toolbag in the trunk.