As others have pointed out, this is pretty disingenuous. Some (all?) of the others are quoting marginal tax rates — and the US stacks up nicely on this front, at least in progressive states: max federal marginal tax rate is 37%, with California having a 14.4% max marginal rate. So apples to apples, the US would be 51.4%.
The problem, obviously, is that nowhere in the world do billionaires make their money through “normal” income.