"I used to be a human being": I like this phrase. It captures, poetically, the existential despair of losing the conditions of humanity. Regardless of if the author's particular conditions necessitates the implicit drama, each of one us, I'm sure, have felt like we lost what made us "real" or "authentic" at some point or another.
People have complained about the loss of authenticity for much longer than the internet (much less social media) has been around. It happens around any time of great change. We happen to be living through a period of some of the fastest changes in human history, so it's not surprising a lot of people are confused and feel like they've lost something.
Couldn't this have been said accurately at just about every point in human history? I'm not asking to try and refute what you said - I think that supports the first point you made. The world is always changing at an exponential rate and we are always on the curve, so people will continue to lament loss of the past until the end of time.