A high population has many of them happening.
Also being a country that backs up other countries that need help, as Americans all have relations in all other countries, which means we stand up for them when in need, and our military is the best for that reason. There are terrorists and megalomaniacs that would kill all Americans if they could, only because they're disturbed and can't fathom what freedom means, being dictators themselves.
Health care is a problem that will eventually be sorted out. It can be just like Canada and the only reason it yet isn't is because of certain people not giving it the priority it needs.
Look at the problems this country has, especially regarding crime, children being lost, girls looked at as slaves, corruption, trafficking of humans, intentional homicide rate, road deaths yearly, daily drownings and electrocutions, along with many other negative things, but living here is cheap, so that, along with the women, is why the majority comes and stays.
If it wasn't for the women here, most would only come for the beaches and food, then leave.
Most gun crimes are gang related and suicides, whereas here knives and machetes kill people daily.
African nations have the greatest amount of children in poverty. 90% of children in poverty are SE Asia and Africa.
The highest obesity rate is in the Pacific Islands, The US. although it's bad, ranks 10th.
Worst carbon emissions is China, US second, then India. More cars, more emissions.
The children in the US have a much better lifestyle than many countries, especially this one.
There are many people who lived in big cities in the US and that's all they know, never or rarely venturing outside into the country areas, so have no idea what's out there.
The US is raked 30th in life expectancy at birth..........https://www.usnews.com/news/best-countries/articles/countries-with-the-longest-and-shortest-life-expectancies.The highest infant mortality rate is in Afghanistan. the US is 165th........https://www.cia.gov/the-world-factbook/field/infant-mortality-rate/country-comparison/