(Disclosure: I work for Google, but these are my personal opinions.)
I deleted my Facebook account years ago. I found it be only noise — a waste of time, with nothing valuable or fulfilling to be gained from hours of using it. I believe that most people use Facebook because of a fear of missing out, or a fear or being disconnected, or out of habit, without stopping to think if it’s a worthwhile use of their time. This opinion led me to discount Facebook.
But over the years, Facebook has built an impressive array of services and projects other than the social network: Instagram, which is a new type of social network. WhatsApp, with a billion users, which has replaced SMS for many people. They’ve branched out into VR with Oculus Rift.
They’ve built AsyncDisplayKit, a library for rendering iOS apps that is supposed to result in smoother apps than the native iOS rendering framework. And ReactJS, a new and fascinating way of making web apps, which they then branched into native Android, iOS and Mac apps. And the Open Compute Project, to share designs of datacenters, servers, load balancers, cooling, and so on. There’s Free Basics to bring Internet to people who don’t have it, and solar-powered drones as another way to access the Internet.
Even if you don’t care about Facebook the social network, Facebook the company is important and fascinating in its own right.