There's also the marketing aspect in North America. People in this continent love big vehicles, and big engines in their big vehicles. The motor manufacturers play to their audience, or market, and produce ever bigger vehicles, and then claim that their big vehicle is the baseline for towing and that nothing else will do the job. I'm not knocking that, it sells lots of big trucks and makes a lot of money for a lot of people, including those that build them.
But big vehicles are not much use in Europe. Gas is four times the price than it is in the US, and the roads are, mostly, not suited to big automobiles. You would have a tough time convincing a European that a huge truck with a gas mileage below 20mpg was what they really wanted or needed. So, they make do with what they have; smaller tow vehicles and lighter trailers.
It's frustrating for me when I hear criticism of folks who don't subscribe to the North American big vehicle trend of recent years when they tow their Airstreams. Using something that doesn't fit the perceived view of a good tow vehicle doesn't necessarily make it a bad tow vehicle. I'm happy that people like to buy into the "bigger is better philosophy", but don't denigrate those who don't hold the same views.