I am originally from Nigeria and I just turned 30 but I went to college in the US and ended up living there for 10 years. I have lived in 4 different cities there and have traveled around the US a lot while I lived there.
One thing that struck me immediately after college was how hard it was to make friends. Secondly, I realized a lot of friends I made did not have old friends. Growing up in Nigeria, I still have friends I talk to from elementary school that I catch up with from time to time and still share a deep connection. I have friends from high school I intentionally travel to see and they visit me as frequently as they can and in college I made life long friends who I talk to every day now. Maybe it was the circle of friends I had but with my American friends, it was unusual for them to have friends that ran that deep. They rarely mentioned people from college and I knew of only one person that regularly maintained a friend from high school. After college, they seemed to be only able to make acquaintances and found it hard to make REAL friends.
In America, I feel people are quick to label things that they do not perceive as "normal" interaction and write it off. Like someone randomly approaching you at a grocery store can easily be seen as creepy or weird. A stranger or acquaintance sharing emotionally charged information can be seen as overbearing/burdensome and so on and so forth. Basically, anything outside small talk and a logical approach gets red flagged from my experience.
This is not the way things are in some other countries around the world. Individualism is a strong part of American culture, which can encourage people to create the best version of themselves, but it also leads to loneliness as we start to self-actualize.
My parents in Nigeria still regularly hang out with friends from elementary school and high school and college. They share their ups and downs and life changes and they are still making and losing friends and they are 60. This is not strange in Nigeria.
Countries who have a communal culture do not suffer from what this article is about, they have their own problems but making good friends, or the ability to are not one of the problems. If people opened themselves up to things that are different from them, were open to serendipity and supported strangers and acquaintances emotionally when they can, they would find friends in the strangest of places.