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.