Everything has it's time. Facebook had a nice run but something will inevitably replace it. Social beings will constantly be craving what's next. Exclusivity amongst college students was what ignited the fire, but younger generations are gravitating away from this platform day by day because it's too complex.
P.S. - people are lazy, and FB makes people work. It's cluttered and doesn't have a core value anymore that Twitter or Instagram or SnapChat can't already deliver. Best bet is to keep the acquisitions going to eliminate competition.