The biggest advantage of a truck bed is the separation of the truck bed from the cab. I can haul mulch, or the nasty rotting wood from an old hot tub in the bed without getting the rest of the vehicle gross. Another advantage is unbounded height constraints, I recently got a heat pump water heater for my house and they recommend keeping them vertical because of the compressor. So I was able to strap it upright in the bed which isn't possible in an SUV.
Sure you can haul a lot of stuff in a mini van or SUV but largely you run the risk of ruining the interior which I would prefer not to do in my vehicles.
Sure you can haul a lot of stuff in a mini van or SUV but largely you run the risk of ruining the interior which I would prefer not to do in my vehicles.