That doesn't make a ton of sense, research shows that social/wealth-mobility is greater in Denmark, compared to the US, by a lot: https://www.rockwoolfonden.dk/app/uploads/2018/03/Om-social-...

The reasoning is pretty much the opposite, the redistribution of health helps to move children out of their parents wealth/social-class. It might be that an individual adult in the US is able to move from poor to wealthy more easily, but I sort of doubt it.