The issue I have with Discord is the lack of threads. When you're helping multiple people at once threads can help distinguish who you're talking to. Or when you have multiple conversations happening at once it stops things getting confusing.

wholeheartedly agree with this. The counter on the top an be annoying as it just aggregates all private chats.

Agree. One huge plus over Slack is that you don’t need a separate account for each community. And joining can be easily done via just clicking a link.

I feel like slack is better for work. But for almost everything else, I just want to check out a channel without the overhead of creating an account.

Could you suggest some ?

http://unrealslackers.org/ https://godotengine.org/community

Both game engine examples but super helpful developer communities none the less.