It seems worse statistically than hate speech, because it widely prevents and distorts communication, and keeps people in separate "bubble" reality tunnels. As Jaron Lanier put it, “This is an epochal development. The version of the world you are seeing is invisible to the people who misunderstand you, and vice versa”.
A bottomless rabbit-hole of paranoia, in which sincere attempts to understand the views of others are seen as insincere or suspect; in which attempts to be courteous and accommodating are mistaken for conspiratorial deviousness or other petty nefarious behaviour. In which people routinely and reflexively attribute the worst possible motives to others, when innocence fits as easily. I've seen friends fall out because of it.
Again, to quote Lanier, “society has darkened a few shades as a result”.
It has a number of causes, some accidental, some engineered. I stopped using social media because of it, but I wonder if it applies to other online social spaces. I've never been a technophobe, I've always enthusiastically promoted technology, so it's difficult to change my mind on these things.
Anyway, back to the real world of coffee, sunshine and birdsong...