Not that different from talking here, except that my FB friends (and especially my FB friends with FB's learned weighting of how interested I am in what each posts) are on average more likely to be interested in the same things I am and have more similar preferences around conversational norms.
That's not to mention that people use social media as a substitute for personally reaching out to friends.
Interesting take.
One thing I struggle with is a diverse set of interests that practically nobody in my life shares with me. A common denominator for these interests is that most were/are cultivated by online content. There is a pervasive feeling of loneliness throughout my life, and I can't help but view the internet with suspicion as a possible threat vector to my sanity. I stay engaged here on HN, but I don't have any real friends here. All of my friends are hundreds or thousands of miles away, and I can count them all on one hand. Facebook and other attention-capitalizing networks provide an empty nicotine-buzz mimicing the real social interactions that I probably need. The idea that social media is toxic isn't new, but I guess lately that truth has been resonating deeper within me.
Consider this: everything you learn about your friends through Facebook, you weren't important enough to be reached out to personally about. THEREFORE! You shouldn't even know those things.