My solution was to delete my Twitter account. I've never regretted it, and feel downright smug when I hear about the latest purity shitstorm in the communities I used to follow.

I use Muted Words and block accounts liberally, to scorch-earth anything that might possibly be adjacent to anything political. This filters probably 90% of what I would otherwise encounter. I don't delete my account because it's a uniquely vibrant resource for game dev and digital art, two of my hobbies.

The actual people I follow are generally really nice; it's just the people they occasionally retweet and then the replies that other people make to those retweets that get into the mud.

Have you found new communities, though? Surely there is some lost value -- maybe not specifically on Twitter, but generally -- when one drops an old group.

The only communities I miss were on old-school forums, not Facebook or Twitter. There could be plenty of drama but not at the scale and virulence of Twitter. I think the reason is that people were more interested in communicating than in signaling.

Huh, that's an interesting approach. My solution was accepting that most people are horribly stunted when it comes to moral reasoning and empathy, lacking the ability and/or will to behave with what I consider to be basic human decency. All of the people that I personally know and consider to be good people find the kind of behavior you're describing just as alien as I find it. None of us understand the universal claim that the Internet as a medium[1] pulls evil behavior out of good people; as far as I can tell, a basic capacity for empathy is a pretty effective safeguard.

I acknowledge that it's a little weird to have one's model of human decency exclude such a large chunk of people from being defined as "good" (whatever that means). But it's grounded in the failure to meet very, very low bars for behavior, ones that most people would claim they agree with. Models are only as good as their usefulness, and it's much more useful to distinguish between those who are capable of empathy and the rest than it is to find a distribution centered around the population median.

[1] Or other forms of groupthink or outgroup homogeneity

It's in my nature to treat everyone as acting in good faith, by default. So when someone would cast a judgement, even a broad one about a demographic, that I couldn't clearly acquit myself of, I would internalize that judgement and direct it towards myself.

This has proven to be totally unsustainable, at least on the internet. Still, I don't think most people make bad judgements out of fundamental malice, but out of a) lack of critical thought, and b) the phenomenon described in the original post where judgement towards others becomes a defense mechanism.

So what I try to do now is neither internalize nor outright dismiss others' vitriol, but to accept that it's probably a) rooted in something real and valid, and b) unrefined by critical thinking and also warped by social pressures to a point where it can't be taken at face value.

Bitter cynicism is a valuable life skill.

(I personally prefer to look at it as not bad and good, but rather loathsome and slightly less loathsome.)

I wouldn't even say I'm bitter. I just think of the average person and average people in groups as forces is nature. You don't get deeply upset when there's a rainstorm, why get upset when you see horrible people acting horribly? Accepting the reality lets you try and avoid/shelter yourself from its excesses. In this case, that means trying to fill your life and your time with decent people, uncommon as they are; expecting as a baseline basically-evil behavior from large groups of people (govt, social movements) unless the institutions are well-designed; avoiding things like politics where the final judgment is people's unaccountable opinions; and understanding how this manifests in individual behavior when you do have to deal with the average person (eg I have no real interest in fashion, but I dress well because I've noticed how incredibly differently people treat you, a fact that's backed up by what studies have been done).

Regarding your "loathsome vs less loathsome" statement: The key point here is that I know people that are very, very decent, and I've had some success in limiting my close friend group to only people like that.

It's not so much horrible people acting horribly as seeing people that seemed to be good (as observed over a period of years) suddenly turning awful.

At least as seen from here, something fundamentally changed starting around 2015, and a lot of people seemed to have lost their moral compass.

These days I hang out with the sinners. Saints are not to be trusted.

Eh, that just seems like a matter of where you set your standards. The environment shifted to slightly reduce the barrier to be horrible, revealing which people were below the new waterline. IMO, if all it took to be horrible to others is a little anonymity and/or groupthink, you weren't that decent a person to begin with.

It's real. And it's spectacular.

Spectacular like a BIG sandstorm, also similarly frightening for those standing in it's path.