Okay so real talk. What's the chat/messenger landscape like right now?
Discord: A ton of gamer shaped folk moved to it and if you're in any kind of net community you probably need it to talk to people therein. Is in middle stages of destroying UX to monetize you. Scummy gamerbro aesthetic all over.
Telegram: Mobile-biased? A bunch of furries went there? Claims to be secure enough to fool people who care a little about security?
Slack: Only really used at work, by people who met at work, or people who pretend to be 'work'. Awful, slow, bloated mess with no mod tools and crap notification granularity.
Matrix: Doomed from the start because you need a massive python binary running on a server you own to do it right. Public servers are overloaded even at this low level of adoption.
IRC: Still there, still what it was 20 years ago. Antiquated in 2019 because it doesn't do mobile, session persistence, or unfurls/embeds.