https://en.wikipedia.org/wiki/List_of_countries_by_number_of...
That is a general pattern in the USA anyhow, a few concentrations here and there but everyone else seems to be screwed in various ways (be it basics like healthcare, education, safety).
But out of the top 10 richest in the US, only the Waltons are heirs. I would say it's a bit of a distortion, since the all of them combined I think is still larger than any other US individual.
Looking at Sweden, it looks like a lot of it is inherited, certainly most of the top 10. And like 1/4 are H&M, Tetra Pak, and Ikea alone. The new 'household names' are spotify and minecraft.
Norway is obviously smaller, but surprisingly, quite a lot of them got the three commas from their own businesses. The last-ditch cop out there is the typical Norway is in general an outlier due to being a highly developed nation with oil money. However, most of the billionaires are not there due to energy.
Also, it's a pretty unconvincing comparison to pick a small population country to benchmark the US against.
https://www.usnews.com/news/best-countries/open-for-business...
In goverment policy there is very rarely a closed form proof of any policy - we are almost always stuck with collecting large and small data points and needing to form a policy based on incomplete information and theory. But mostly it seems it’s matched up with motivations and biases - which are worth examining.