For some crazy reason, which I believe was all my friends stepping backwards when they asked volunteers to step forwards, I ended up running a small-medium sized gaming community for several years. Website, Wiki, BBS, Teamspeak, Calendars, Events, etc. So I have a good deal of experience in this matter.

The vast majority of communications that take place, in my observations, are:
1) text messages - just people text messaging in a channel that may or may not be about a specific topic.
2) Memes & Videos - posting links that turn into pictures you can see right in that channel and links that turn into embedded video so you can watch it there.
3) Voice Chat - multiple voice chat channels where we can control the voice quality.

Using a BBS or contributing to a Wiki were done but in such small amounts that it was negligible. Nobody wants to dive through a hierarchy on a BBS to post in the correct place anymore. We had them and it was barely used. Our users just dumped stuff that could have went there into the text chat area of whatever voice chat tool we used. They didn't care to expand the knowledge of all the other users, they just wanted to send it to a close friend or two they happen to be talking to at the time.

Above all, I'd say around 95% of the users will NEVER pay for anything. Donate to keep the Teamspeak servers online? Nope. They have money for a gaming rig PC and monthly subscriptions to a MMORPG, but 1$ per month to keep the lights on? "Sorry, can't this month." When the last of the 5% that is willing to pay leave, it all comes crashing down and the lights are all turned off. Deleted.

That brings me to Discord. Say what you will, but it accomplishes all the requirements. Texting, Memes, Videos, Voice, & it's FREE. Bonus: Game Streaming to your buddies, & Bots to do things like Application Forms or to Play music in the Voice Chat. And there's a phone app, if that is your fancy. I know some that used the phone app for Voice Chat by using their cellular data so they could focus their slow PC connection all on the game.

Is Discord the perfect communications app? No. But is it good enough? Yes. And that is mostly due to it being FREE.

I migrated that community that used to pay some hosting company about $120 per month over to Discord when all the Whales (the 5% that paid for things) left. Long before that, I was reducing plans & cutting unused Teamspeak capacity. Had it down to less than $20 per month. But it was just one guy that was paying for it. Eventually they stopped. I was able to build out what we need in Discord in about 2 hours of work. Honestly, Discord was the only real option. Me and two others did research. The other options just did not check all the boxes for us. YMMV.

Personally, I hate the way text and voice channels are displayed on a server's side bar in Discord. Very confusing at first because only difference between them is a small icon to the left. But past that, the text channels are very SMS like and it feels like you are just in a group chat on your phone. Probably why the young users like it....and if they use the phone app then it is merely just another chat app they have used. IMHO, the "targeting" Discord did at young users was simply making it look & feel like a phone app.