What is the advantage of a open bed?
In Europe the role of a small commercial vehicle like this would be taken by something like a Mercedes Vito or a Ford transit connect. I really can't think of a reason why you would choose a TELO over a Nissan NV200.
If you haul dirty stuff, it’s much easier to hose out a pickup than a cargo van or suv.
For a half way point between tent camping and pulling a camper/caravan, slide in campers work with pickups but not cargo vans. If using a cargo van for camping, you probably want something that allows you to stand. That calls for a high top or a conversion that adds a pop top.
Yes, in the UK pickups now seem to be status items. I don't think I've ever seen an open bed used. I've seen a few towing big trailers, that's about it.