With 2 billion monthly active users… I think a response needs to be far more thoughtful than “Do they, though?”
Of course they do. Social networks bridge the gap between publishing and communication for the public in a way that has been absolutely transformative in many people's lives, and many people do want that and find that useful. People want to chat with and share media with their friends and affinity groups. They want to follow trending or interesting subjects. They want to post cat pictures and memes.
Outside the SiliValley bubble, though?
Of course outside the bubble. It's really only on HN that social media is assumed to have no redeeming value beyond acting as a platform for corporate mind control, propaganda and culture war, but for most people social media is just a way to communicate and stay entertained. My mother, who can barely even use a computer, keeps in touch with her relatives and gets pictures of her grandkids and keeps up with her COPD support group on Facebook. Obviously social media has value to her and many, many other people.
Do you honestly believe only California techfolk use Facebook?