I dunno if ratio of median to mean is a great measure. The best we can do for a comparison like this I guess. And I would consider Russia, Turkey, Ukraine, and Thailand as developed countries with worse wealth inequality, but the US still ranks 9th most unequal by this measure.

Interestingly, the Netherlands comes in at 153rd. And when you look at income inequality at the World Bank, using the GINI, it comes in at 154th there too. Coincidence, I guess. The WB GINI data has the US at 54th worst. But the WB data is income, not wealth, and wealth inequality is much worse than income inequality in the US, largely because of long term low tax rates on the rich.