I used to be a pretty prolific multiplayer gamer back in the days of server browsers. I met some good friends across many different games. Nowadays I pretty much only play single player games, with the exception of racing games, in which I don't talk to anyone. Matchmaking is the main culprit for this. It's so much more difficult to make friends in online games than it used to be, because you're only together with the same people for one game at a time.