I would imagine that wealth, cultural homogeneity, and a very small population accounts for at least 80% of the explanation. So not the “whole” explanation, but the critical mass of why it works, sure.

It’s questionable to assume that Norway’s system could scale up by a factor of even 3x, let alone something sixty times the size. I’d be interested if it could produce results in a country like Spain or France with 50m people before calling on the US to simply do what Norway does but with 350m people.