Because vehicles are a compromise. A truck can do everything a sedan can. A sedan cannot do everything a truck can. A flatbed truck can do more than a smaller truck - but it also is bigger and not easy to drive because of the size. The costs to own extra vehicles is very high and so people won't own different a vehicle for each use (renting is not a good answer - too often I've gone to rent something and it was sold out. Also most rentals have restrictions on use)

> To me trucks are the most useless type of vehicle apart from niche utilitarian cases in farming or construction. Super heavy, gas guzzling, open bed, compromised handling, pedestrian crushing death machine. If you want big family hauler, grocery getter: mini-vans, wagons.

Minivans and trucks get similar fuel mileage. For the average family there are not enough kids to need a minivan.

> If you are in trades: van, box truck or flatbed box truck (where bed is useful shape and size, and all sides can be removed if needed).

Obviously you are not in the trades and don't know anyone in them. I've heard plenty of people in the trades debate the merits of truck vs van. They are compromises and there is no clear winner.

> you don't need 3 tonne vehicle with bajillion horsepower as a daily, because you may need to pull a trailer with your inflatable dinghy once in a two years.

If I need to tow something even once every two years then I need to own a truck. I've tried to rent a truck to tow something - turns out most rental contracts don't allow towing. There are exceptions, but the cost is so high, and finding a place to rent is so inconvenient that I will just own my own truck instead - it is worth it.