The downfall of Facebook is what was the crux of its initial success: the comprehensive largeness of one's social network. On Facebook, most people accept all acquaintances and friends they have in real life (should they get a friend request)-- it would be rude not to-- and as a result, one's Friends List is usually a pretty good indication of one's entire social network. This allowed Facebook to gain its initial network effects, but this is also now paralyzing the activity of its individual users. I feel uncomfortable posting extensively online because there are many people in my friends list who I feel uncomfortable seeing my things (and I don't care enough to create Private lists).<p>As far as addressing the teen exodus, and related to the above impact, Facebook's NewsFeed is just not interesting anymore. Back when Facebook started, I was friends largely with 100-300 people whose lives I actually was interested in. I am not interested in the minutiae of my current 1000+ friends' lives, and their endless and meaningless statuses bore me to no end. Facebook wanted its NewsFeed to break out of the echo chamber effect, and therefore made the NewsFeed algorithm more random, putting the onus of creating relevant NewsFeeds on the individual user (through the creation of individual lists of friends). But USERS WANT THE ECHO CHAMBER EFFECT! I don't want to know what's happening in the "town square,"-- I want to know what's happening with my 20 closest friends. Because teens joined on when this new paradigm was already in place, there's nothing to draw them in. It's just not interesting-- and apps like Instagram and Snapchat are more engaging as a result because they're more personal.<p>Lastly, Facebook is way too cluttered. It has an atrocious UI, so many buttons all over the place. Mark Zuckerberg's utilitarian aesthetic lives to today, only it's way worse because Facebook has so much more (useless) functionality. Instagram and Snapchat are clean and elegant-- it's not jarring to open those apps like it is to navigate Facebook.