[leereeves]

About half of the pictures of Sprinters with flatbeds that I saw on [1] have added side walls. I guess their owners found some use for a pickup so they made their own.

Between the two designs, I'd rather have a pickup. With a flatbed, I'd worry about things rolling/blowing off.

The fuel consumption is a separate issue; there are pickups that get good mileage. But that was (until recently) less of a concern in America because we had lower gas prices (and for the most part, the people who buy pickups don't worry about climate change).

1: https://duckduckgo.com/?t=ffab&q=sprinter+with+flatbed&iax=i...

[Glawen]

The sidewall are there to hold the load, you need also to secure the load by attaching it. Moreover they come with tilting mechanism to unload (sidewise or back wise). This I think is not possible with a pickup truck.

It is very useful when you destroy a wall, you can haul the brick to the junkyard, or if you bring sand in bulk for building a wall.