When you run on your own, the chances of that are zero. Personally I can't imagine doing track-style intervals alone.
You can talk as much or as little as you want. Some group members are "hi and bye" while others become close friends.
If you live in a city, it also helps you know & understand your city better, and be a more well-rounded member of your community. Even casual conversations push the needle that way. Social cohesion and all that.