Email has been the major communication vehicle through my career. The work team I joined a year ago uses Slack. Our employer's official vehicle for "chat" is Teams. My team's high school interns prefer Discord. Some friends use FB Messenger. Others use text.
I have no preference. In the end, all of them can send messages point-to-point or broadcast. You can share documents in all of them. (I haven't tried it in Discord but I assume you can.) I can communicate and get work done in any other them.
Just a few observations.
1. Trying to figure out who communicated where can become challenging.
2. Better integration with "productivity" apps can make 1 less challenging. For instance, a co-worker requests a new API by a certain date. If it's done in Slack, for example, it would help to have it appear in my task list without my having to add it manually. Likewise, a friend sends a message in FB messenger about a cookout: having it go to my calendar would be helpful rather than my remembering a week later which app she sent the message in so I can put it on the calendar manually.
3. My employer is notorious for abusing email. We have message threads with 10-20 people and dozens of replies. Often I would love a way to opt out: a real opt out, not a reply with a request to Reply All minus me. Not having this feature is a deal breaker for email going forward IMO.