[feteru]

Except almost anything you do can be the beginning of that engine. Joining sports team, hobbyist group for anything will lead you to meet people, through whom you either meet or hear about other events. Strong network effects once you get going but you do need to have time to show up consistently and in a good spot

[watwut]

Many sports teams don't build all that much of friendship outside of training and competitions. They are acquitances with no other investment.

The moment you get injured or sick, friendship is gone. Same goes for hobby groups.

[recyclelater]

This is a very cynical take and I would recommend some self reflection. I know for a fact you can make lifelong friends from shared interests. I’ve done it, I have friends who have done it. Maybe it’s harder for some but it is absolutely common.

[watwut]

I mean, I was member of sports teams. Sometimes lifelong friendship evolves, but it is not nearly automatic nor super frequent.

Way more likely is that when people stop going for whatever reason, the relationship ends. Getting injured or sick or having new kid and less time or whatever all means you disappear.

[recyclelater]

This is a function of your skill and desire not a deficiency of the social activity

[watwut]

What part of that observation is about a skill or desire? I mean, I am describing what I observed to happen to people around me. If too many of them are "not skilled enough", then maybe it is not just about individual failures.