It’s almost like that it isn’t the intended purpose of these vehicles… you don’t need 19ft long 10ft tall super duty ford f-250s and up to pull a 4klb trailer though… a 70s f150 half that size could do it just fine and modern engines in that size vehicle would be even better
Kei trucks and vans are the perfect vehicles for most jobs and most tradesman not hauling loads meant for real trucks not light truck frames
Most tradesmen DON’T use a 250 Super Duty unless they really need one. They prefer the standard 1/2 ton base models because they are cheaper and “good enough”.
Kei trucks, while they do have their place and uses in some cities, are NOT the “perfect vehicles” for most tradesmen in many parts of the world. They do not carry enough items and tools for most tradesmen to make all the repair calls they may need to do in one day. They often need to drive well over 100 miles a day to get to all the appointments they can have. And the design of the those little trucks are patently unsafe at highway speeds.
Vans are sometimes popular, but they are just weird looking trucks. And they can be difficult to access tools and items from. Requiring you to either unload a bunch of stuff to get at something or you need to crawl over everything.