I think in our single digits we play and play hard and that is good.
In our teen years we fight angst and work through cliques and social situations.
The twenties are great. These are the years of using the knowledge learned in the teens to just have fun. We aren’t trying to game the system or social climb yet. We are comfortable with ourselves and willing to give unconditional time.
The thirties are either aggressive corporate ladder climbing where “who you know matters” so people suddenly gain “value” and therefore you must selectively choose who to spend time with based upon how much you can gain from them OR you have found a comfortably place in your life and are just doing the pattern which like the NYT times article states doesn’t include refilling your pool of friends as it shrinks.
The forties, at least for me, have a huge family first focus. While friends are important, family has to come before all as you realize your children are growing up fast.
I cannot yet comment on the fifties and above without playing off comedic stereotypes.