Americans are (generally) just shitty human beings. This has been true since the first landing of the pilgrims. Yknow, the gang who were famously religious extremists considered too extreme for 1600s Europe.
This is the natural outcome of an individualist society. Similar to how capitalism will always result in total economic collapse, individualism is a poison to society.
Even going back thousands of years, people generally helped each other out. You can go to a random village in the Russian countryside where people live in desperate poverty and they’ll share some food and water with a smile on their face. This is generally true anywhere in the global South.
People depend on communities and societies. America has systematically destroyed all semblance of the human experience, and it shows.