Like idk. I think the whole "digging up dirt on someone you slightly dislike to justify why you're correct rather than annoyed" and "they should have done xyz to make up for it. No not like that" and the rush to distance yourself from even the slightest unsavory facet about a person you have never met IRL is damaging actually.
MORE than in the sense of "you shouldn't do that." I think most rational adults can agree that being parasocial is bad and obsessing over mistakes and poor taste and botched interactions is detrimental. Callout posts and anon hate and so on are bad. That's a given.
But I think the prevalence of that culture is negatively impacting even people that don't participate in it. Knowing there's a subset of people out there who WILL skewer you for the slightest infraction, or WILL hold an unforgivable grudge against you if they find out what you did years ago, has to make it REALLY FUCKING HARD to afford yourself any grace, right? Because there's that looming implication that you're damaged forever if you step a toe out of line.
And I think that's what leads to people having a panic attack about being wrong about something. Or being called out for bigotry. And maybe also contributes to the whole hyper-aggressive protectiveness of characters and media you identify with. Like, ideally, you admit you were wrong, you grow up, you move on. But how do you do that if you've got this deep-seated fear that if the people you cared about found out, they might be part of that unforgivable-grudge-holding subset?
Idk. Am I making sense? I think I'm making sense.