No, we've had several experienced users immediately disengage because they felt overwhelmed and/or confused (not using as synonyms here, but common related reactions) by the interface. Performance issues, especially on mobile, haven't helped. Most people are just annoyed that you aren't using their favorite chat app already.

Zulip is promising but I think there's a little bit of a bubble around it here on HN. In the real world, its reception is much more mixed, and outside the context of software development, topic threads are awkward and difficult to manage.

Not the only one for sure, but I suspect that the big reason people are confused by Zulip is that they're already used to another, different chat service and don't remember how confused they were by it in the start.