> [...] the US is still probably the best place one could possibly live inclusive of all factors. There is a reason we're a net importer of people rather than a net exporter.
The first sentence is a highly subjective opinion, and the second one is biased. I'll try to bring some (factual) dissonance.
Most immigrants into the USA come from Latin America and Asia. I haven't found recent immigration balances between the USA and other rich countries, but I doubt it would always be a net import to the US, especially if one considers permanent immigration. For instance, more American citizens (120k) live in Australia than the contrary (90k).
As for the USA being the best place to live, it's surely not based on life expectancy. Even the CIA world facts ranks the country after the 40th position, with many English speaking counties better ranked. The obesity rate of 39% is probably the largest factor of this lower quality of life.
Now for a subjective opinion, I like my way of life because I live in a town where I can walk/run to the nearest mountain in half an hour, I go to work on a bicycle-only road, I buy fresh food in a nearby open-air market where farmers sell their own production, I only use my car on week-ends... Many countries offer all this, but I suspect few places in the USA could compare. And when I went to dentist this morning, I did not even bring my wallet, because I knew that, like almost everyone in the country, I don't have to pay for basic care.