I think part of it is the rise of online echo chambers. People act like the media they consume, and latter generations grew up with online circle jerks being the norm.
Another factor is the rise of so much bad faith disinformation coupled with the extreme virality of bullshit on social media. It seems like the truth of a story is inversely proportional to its likelihood of being shared on Facebook.
There's been a panic about the explosion of things like Qanon, neo-fascism, and anti-vaccine disinformation. I hear a lot of people questioning whether it's possible to have a liberal open society without... ironically... censorship.
I don't think censorship can be the answer, but I don't know what the answer is. The last few years has left me utterly shocked at the gullibility of human beings. Do people even think at all or are we indeed just mindless "meme machines" whose central nervous systems are vectors for replicating patterns?
Censorship of those who seek to oppress is necessary to require freedom (or to put it another way, the paradox of intolerance is that you must be intolerant of those who are intolerant, to guarantee that maximum tolerance is not only possible but guaranteed over a long time frame).
On the note of meme machines, I always liked to think that Memes ought to be studied in a university course, Memetics could become a serious field of study.