That would be your anecdote. I wouldn't make the assumption that Facebook is being disrupted (by what? Snapchat?)
Been on Facebook since 2005 (after I left college) and I'd say that it's busier than it has ever been. A huge chunk of my social sphere uses it for photo and link sharing; it has completely replaced mailing lists and instant messaging of years past.
Maybe not disrupted but certainly unbundled. Facebook still serves as a central umbrella or hub for keeping track of all the people you know and meet (basically a contacts list) and an easy way to message acquaintances whose email you do not know. Other than that, it's much less engaging. News Feeds are wastelands with nothing but memes and vines and the only people who seem to share are the annoying ones nobody wants to hear from anymore.
Been on Facebook since 2005 (after I left college) and I'd say that it's busier than it has ever been. A huge chunk of my social sphere uses it for photo and link sharing; it has completely replaced mailing lists and instant messaging of years past.