Added to my reading list, thanks! I'd wager that the "self esteem" movement, or more accurately, whatever caused it to gain traction in the American psyche, kicked off the downward spiral to where-we-are-now.
In a nutshell, several generations of American children were taught, systematically, to ignore social signals that conflicted with their self-image, and were thus deprived of a very critical part of their childhood: in where they learn to moderate their behavior in order to get along with other people.
Self-esteem education was based on the (correct!) observation that people with high self-esteem are healthier and more successful.
Given my extensive experience with educators, I am not in any way surprised that the conclusion they reached was that high self-esteem must cause health and success, rather than health and success resulting in high self-esteem. Educators seem to have this anti-Newtonian view on the world, in which reactions cause actions. But I digress.
I was subjected to this as a child, and it took something on the order of a decade of living abroad -- mostly in Japan, a country which, lacking any concept of "self", offers no affordance for "self-esteem" -- to fully realize the sheer horror of what I had been steeped in as a child.
As to why this has come to a head since the advent of social media, well, we're at the point where an entire generation which socializes primarily through virtual means has come of age.
When your social interactions are driven by proximity -- e.g., you are limited to people that physically exist near you -- then you are forced to learn some degree of moderation. Because if you can't get along with others, you find yourself rather in deficit of friends.
But now, it doesn't matter how crazy you are. If you worship Mao or Hitler or Stalin or whatever, there is a community for people like you.
No amount of ostracism will remedy this. That worked when your ability to make friendships had real, physical constraints. In the fully-connected schizophrenic hivemind world of 2020, casting people out of your tribe will, at best, only deprive them of a moderating influence.
Still not sure where this goes, but I am fairly certain it's got at least thirty-one flavors of ugly.