I'm really grateful we never had mobile phones in my youth. Used to catch trains, visit coffee bars, record shops all friends in tow for meet ups, chat about variety of things.
Having children slowed down with get together over rugby games and braai (bbq) together on weekends. Older you become many move or are departed, sometimes luck be it you make a new friend or two, not often by then you pretty set in your ways.
Uber is a killer of random also! People can even choose through the app not to talk to the driver... sad world.
And yeah, age plays a part as life changes, people move and it is natural. But if we think about how we evolved, we were with the same set of people for life not too long ago. I don't think we are made to have a completely revolving door of social life.
Deep down I think many are much the same, worldly ideology has changed leaving many young men especially totally confused. Rapid change has negatively influenced many.