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.
