That just isn’t true. Meeting a stranger, realizing you enjoy their company, trading contact info, deciding to spend “structured?” time together. This is most of my friendships and all of my relationships after university.

Only the first meeting has to be incidental. Expecting all future contact to be incidental is how you let all could-be friendships and relationships pass right through your fingers.

Take a little control over life.

I met a very good friend of mine in line at a restaurant. I'd argue it all comes down to your mindset - I'm not even that extraverted. At least in the midwest this is incredibly doable and common.