To be honest, few months back I’d probably have the same perception as you since I only see young teens using Snapchat, especially those in the international schools.
But since then I am seeing more and more young adults using it too. I’d say the experience itself is much more immersed and especially to be able to “follow” people lives in an almost real time and uncensored video feeds — is a very rewarding experience, at least for me.
The uncensored part is very important in the experience since the snaps will disappear in 24 hours — people are posting anything & everything, and all the time.
Problem with the content fatigue (viewing all of your followings) might be true if you have hundreds of friends, but again, talking about the uncensored feeds — I won’t actually be allowing all people to view my feeds and vice versa.
I’d say this won’t be a social media for every age (like Facebook) but this is the social media for the smartphone generation between the age of junior high school to the young professionals.
A perfect social media in between the pretty pictures (Instagram) and live video (Meerkat or Periscope).