You really have a very limited imagination, don’t you?
No, I have an excellent imagination.
Drive around in comfort and with 4/5 seats. FAIL they aren’t comfortable
Have a sizeable boot for storage without worrying about muck. FAIL smaller than a van
Stick on a rear box and have a healthy estate car. FAIL worse than an estate car in handling, economy, comfort and performance
Demountable for weekends away. WOT?
Hitch a caravan for longer journeys. FAIL loads of cars are good towers, if you need a gigantic caravan then get an SUV
4WD for those trick moments. FAIL it’s available on many other vehicles
Not so fast that I’ll lose my licence. FAIL so are lots of other vehicles
Good handling. FAIL it’s just wrong
Nice high driving position. FAIL also available on vans and SUVs
You might like all those things, but other vehicles do them better. As I said, a pickup is only best IF you need to carry difficult loads on difficult off-road.
Difficult off-road in general – 4×4
Carrying loads in general – van