Earlier quoted context omitted.
If all you want on top of Discord/Slack is proper topics, https://zulipchat.com/ is worth a try. See, for instance: https://rust-lang.github.io/compiler-team/about/chat-platfor... https://www.ponylang.io/community/ (both use zulip for their main chat platform, AFAIK)
I want the social graph. I post, only the people I added as "friends" get to see my post, not everyone who signed up for the discord/slack. I also only want to see posts from my friends. But of course, we all have different lists of friends. Discord/Slack don't seem to be about that. But thank you for the recommendation. I'll still take a look
If anything it provides a more specialized, focused, social graph. That's not saying it's better or worse than Facebook's approach. I generally expect someone to answer a post I put on discord "in real time", to accomplish something.
What's good (and bad) about a Facebook post is that it allows me to just throw out an idea and any one of my many friends, from many circles, can respond.
I wonder if a discord that allowed general broad also would be interesting.