I don't think it is a simple problem. Much like TODOs, everybody has their opinion about how a chat app should behave. Zulip seems fine, but it's not that uniqu

I don't think it is a simple problem. Much like TODOs, everybody has their opinion about how a chat app should behave. Zulip seems fine, but it's not that unique either, there is also Twist and I can imagine that many of the other competitors do too. Note that Slack has threads too but they are different, Google Chat also has threads but they are not named.