I still kind of struggle to understand why Slack is so popular within the corporate world. It is a good choice when you have some public initiative and let people swarm in, yes. But when it comes to private entities(I'm talking about large corporations), I really don't get it. I've been using MatterMost for years and while it had a rough start, at this point I'd take it over Slack any day of the week. Functionality is pretty much the same, integrations are much more simplified(I use them a lot to say the least and from my point of view, all the API's work as a charm) and at the end of the day, you are the owner of your data. So it is a genuine question: What gives?
In a lot of corporate environments, "self-hosted" is not an advantage if you're the one trying to set up something new. In order to self-host, you have to go through your corporate IT department to provision servers. This alone can take 6 or 12 months, and you still have to find someone to maintain the service.
And the kind of companies that value self-hosting will usually want this to be set up inside the company's internal network. So you'll have a bunch of firewall issues to get through, otherwise good luck getting your users to connect to some non-publicly-accessible server from their phones.
Other comments talk about how Slack nailed the UX for users to join a Slack workspace. But they also nailed the UX for getting a workspace set up in the first place.
(Well ok the whole idea of separate accounts per workspace thing is a bit of a mess, but they nailed everything else)
It took _forever_ to get a self-hosted Jabber-based chat client going at a mid-sized corporation, about 10 years ago. Someone went “rogue” and set a server up anyway. Our security staff began blocking ports, so it eventually died anyway... in favor of Skype and Yammer. All because no one wanted to host chat history and a server.
Nope, so far I haven't come across a single Atlassian product I can even mildly tolerate so I'm not putting faith in their products unless I have to. Lync - I'm a full time linux user so that's a tough one to say the least.
