Microsoft Teams is the same, but in certain tech circles MS Teams seems to be hated.
As someone who's staunchly in the Linux camp, I don't have any strong feelings -- I use MS Teams and it's ok. In the corporate world people are ok with it too.
Which brings up an interesting cultural disconnect: people in tech use different tools from folks in the non-tech enterprise/corporate world. As someone who straddles both worlds, it's an interesting divide to observe.
(Side note: this is also why many tech folks vastly underestimate the influence of Azure in most enterprises, which always seemed to me to be an interesting blind spot. This seems very similar to the blind spots that occur in politics.)
[EDIT] also like Asana, I gather people who were in it & related MS tools basically all day—so, managers and similar—thought it was fine.
It does not have to be that way but it is very easy to end up that way.
First I've heard of Zulip, so perhaps I'm misunderstanding what you mean by thread.
It's like if you had one channel per topic in Slack, only they're much easier to follow/mute/display.
> Couldn't you achieve the same by namespacing Slack channel names?
You could, but that's super heavy. In Zulip, creating a topic is as easy as replying, and everyone in that stream sees the topic by default, so you don't need to invite people to each one separately.
The most accurate simile really is "Slack, but everything in a channel is a thread, no messages".