[SlowRobotAhead]

> It would be catastrophic.

Yea! How did people communicate or companies advertise before Facebook!? They couldn’t.

I mean, maybe some old fashioned things no one remembers, but we’d be talking all the way back to 2004 here.

[SquareWheel]

You've managed to ignore all possible context and depth in your sarcastic answer.

The question is not "Could Facebook be replaced?". The question is "What happens were it to disappear one day". They're different questions with very different answers.