What does this 2020 Economic Mobility Index say about the equality of opportunity and the efficacy of Democratic Socialism?

The 2020 Social Mobility Index was just released at the World Economic Forum. This metric is designed to measure how easy it is to move up in society from the class you were born into (i.e. “the American Dream”).

If you look at the data, the US has an index of 70.4, ranking in 27th place out of 82 countries. If one looks at the list, it seems that democratic socialist countries following the Nordic model are topping the list, suggesting economies pursuing democratic socialism produce the most equality of opportunity for their people.

Do you agree with this conclusion. Is there a better way to interpret this data?