Not sure if we can compare the European wealth distribution with the USA wealth distribution; they are in separate categories. But I agree that wealth distribution has moved up a notch in Europe. Still, nothing compared to the USA.
The political system has something to do with that: In the USA, winner-take-all is the system in place, and it is therefore no surprise that the winners are getting more and more and more.
There is no grounding force in winner-take-all.
US Senators are voted in on average with 60% voter support. That means that 30% gets their Republican Senator, 30% gets their Democratic Senator, and 40% goes home empty-handed.
This should make it very clear that democracy in the USA depends on 30% of the voting population. It is an elitist democracy.
In Sweden, the majority is based on 50% of the voters; it is grounded, based on all voters. In the USA, the majority is based on 30% of the voters; it is not grounded, competition for competition’s sake.
That is why the outcomes are more extreme in the USA. The voters are not given equal values like they are in Sweden, the Netherlands or Spain. Voters compete with voters to get represented, and the majority wins and the large minority gets nothing.
The one nation in Europe with winner-take-all is the UK, and it may be good that Brexit succeeded. Margaret Thatcher was able to yank the European economic playing field toward a libertarian high&low, and it would be great news if mainland Europe sprung back toward its more social-democratic traditions. I have seen the first signs already, but it will take 5 to 10 years to really see this happening.
'Majority Rule'