I see it just as extension to "cancel culture" in IRL society. Nothing complicated just same stuff pushed from media comes to the web. Much helped by algorithms that are supporting it.
It is not only reddit, whole public internet is just an echo chamber, with no critical opinion allowed.
Every topic in current society (at least Europe+North America, I don't know what's happening in the rest of the world) is either black or white and no in between. Very scary place we are in currently. And people put you in some category just based on one sentence, one though, one idea.
I don't see anything special here or on reddit that is not happening in other parts of our society.
Maybe fediverse is so clean you can see it happening live, just look at any defederation request and what they think of different opinions. Different opinion is forbidden. I never thought we will ger to this point, I believed internet will give us freedom of speech and freedom to discuss. But so many topics have become dangerous.