As a fellow non-American, it took me years the realise there is no America. It is the Unites STATES of America, where the states are all very, very different.

As an example, last I looked the GDP per capita in San Francisco is $48K, whereas in Miami it is $24K. That is a pretty massive difference, and leads to very different outcomes in a lot of areas.

The best way to think of the USA - and China BTW, which has an even worse demographic spread - is to compare it not to one country like England, or Croatia or the Czech Republic, but to the EU as a whole. Luxembourg is Washington DC, Switzerland is Connecticut, London is New York, Seattle is Berlin, Croatia is Alabama and New Orleans is Barcelona. Those are not exact comparisons, but just a framework for understanding how aggregate US results are so weird.

Because even healthcare, if you combine the population Conneticut and Massachusetts, it is the same as Sweden's with very similar outcomes. Alabama and Mississippi, on the other hand, aren't doing quite as well.

TL;DR, The average for the USA is really misleading, as the spread is much larger than it is in smaller (area and population) countries.