Brutal opinions follow:
1. Actually, social media is fading. The cutting edge audience has bailed to chat apps. The even more cutting edge audience is going entirely offline for anything serious.
2. Email will remain vitally important as a means of conducting business and actual communications; for socializing, people are choosing social media or chat apps.
3. Many of us still write letters because there is no better way to deliver a personal or formal message. There is a large crossover between the anachronistic behaviors of pipe smoking, using fountain pens, and living outside the herd.
4. Yes, civilization is still failing. It's a long process (see Toynbee, Tainer, and Gibbon). But, it is also inevitable once society moves from a tacit agreement of purpose to an explicit, symbolic one, and culminates in caste revolt and democracy, which then move it into its final stages. But some always break away, and it seems our civilization is fighting back for its life, or at least the remnant of sane people are.
Cheer up. War is on the horizon, and death and chaos soon follow. But through fire comes transition (and not the Bruce Jenner kind). Merry Christmas!