What's the criteria for relevancy, if not "do people still use it"?

Are you innovating? Are you top of mind for people? Is your tech transforming people's lives?

I use electricity every day. Is electricity relevant in most contexts for me? Nope. I drive a car every day. Is the type of car I drive relevant in any way? Nope.

Your life as you know it would disappear if electricity stopped flowing tomorrow.

Facebook is no longer the trendsetter but it still influences the daily lives of millions of people and will probably, once again, have a major impact on who the United States next president is. Facebook is highly relevant.

Would your life as you know it disappear if Facebook disappeared tomorrow?

Facebook is a cancer to our society. Luckily it looks like most people moved on an now it's a ghost town.

You're confusing sufficient with necessary. "Your life as you know it will disappear" is an absurd necessary bar to determine if something is relevant or not.

> Luckily it looks like most people moved on an now it's a ghost town.

Ah, you're just unaware of Facebook's DAU/MAU trends. They're not hard to find.