Uses between 6 and 7 liters of gas. Which is better than your pickup truck

But worse than a modern diesel wagon or even midsize (huge by European standards) crossover SUV like an X5. I guess about the same as a modern petrol wagon like a Passat Variant then? Which can transport way more stuff, fit adults in the back seat and should even be able to tow a medium sized trailer (not a huge motorhome obviously).

We've come a LONG way in efficiency for internal combustion engines. Pickup trucks suck, but outside of the US they're not very common daily drivers anyway... and we have smaller ones. 2.0 diesel Ford Ranger is about on par with the fuel economy you claim for the Polo (is it really THAT high?). Same for some variants of the Toyota HiLux.