I think our definitions of "interesting" may differ. If we take the angle of hobbies, for instance...

I would say that picking up running as a hobby can provide many social benefits. It's relatively popular, it's virtually omnipresent, it's considered by many to be a 'morally superior' activity, it's likely to make you more attractive in the dating department.

But I wouldn't really call a person interesting only due to having running as a hobby, nor do I consider running an interesting hobby.

Most people, on average, haven't had too many experiences or interesting hobbies by virtue of being the average, but I haven't found that the average person has issues socializing. I'm not sure if being interesting is really all that related to that.