This is indeed nauseating, especially when you consider that the USA is not even in the top 10 in many human development measures. The reflexive tribalism you see on the right makes me think we must be number 1 in self esteem.
OTOH the U.S. has a much more diverse, wideranging population and geography than countries ahead of it in those measures (that I think) you're thinking of. Regions that would be different countries in Europe or Asia are all states unified under a federal system, which has its upsides and downsides.