I think Zuck realized pretty fast that specialized competition is coming that's why he scooped up Instagram and WhatsApp so fast. Without Instagram and WhatsApp, Facebook is botched, something like Google without Chrome and Android. I really can't see how Facebook can become relevant again, their time is gone, people got tired of it. Like you said it was awesome back in the day because it was the first real social network and everybody was on Facebook but nowadays no way 90% of your friends are on Facebook. They are scattered around, mostly on Instagram, WhatsApp and Snapchat. Zuck got lease on life when he acquired Instagram and WhatsApp because they are still relevant and will be for quite some time.