there is no use case where a pickup truck is better than something like a kei truck
I like the mini-trucks like the Kei, they are practical and useful for light loads around town. What they don’t do is heavy loads and / or long distances.
So here’s a “use case” where my full sized American pickup truck is required. Several times in the last 6 months I’ve pulled a triple axle trailer weighing 12,000lbs (5,440 kilograms) a distance of 200 miles (320 kilometers) at an elevation of 6,000 feet (1,828 meters) ). Assuming the weight didn’t collapse the rear axle or buckle the frame on a Kei then trying to actually pull the weight would certainly destroy the transmission and / or engine.
If you want to discuss “cargo space” then ALL pickups, including the Kei, suck. Holding cargo internally is what van bodies are for, not pickup bodies. This why city based tradesman the world over drive chassis with van bodies.
So called “Off Road” is a whole different can of worms, nearly no one really does it (even if they think they do) and I’d submit that NO mass produced pickup is truly suited for it as real Off Roading is done with vehicles specialized for the terrain they are working in.
Mini-trucks are great at what they’re meant for but they aren’t meant for everything.