I started using Discord in 2015
Back when Warframe had raids and none of my friends had ever heard of Discord.
As people who have listened to the early episodes of my old podcast (back before I knew how to edit audio) will know my online friends and I formed a community that had named itself Melonmancy (hence the site name), and back in those years to have a community survive you needed a place for them to gather. For us it was our Teamspeak3 server, then later our Mumble server which were supported on the side with our NodeBB forum. I self hosted both of these servers on spare hardware and was solely responsible for fixing the outages. We used some web hosting for the forum. This was the beginning of my desire for something different.
One thing Teamspeak3 and Mumble have in common is lack of chat persistence. When it comes to the text chat of the voice channels - if you weren't there, then you didn't see it. You had to be committed to the discussion by connecting to the channel even if you simply muted yourself later or didn't even have a microphone. It was culturally accepted that you just gotta be there to be part of the team. Discord doesn't work like this at all. I realize in 2019 there's a large demographic of people who use Discord that may never have set foot on any other voice comms server such as Mumble, so if you don't believe me I have an old cringe video where I tried to teach my fellow community co-founders how the permissions worked - I may have been drunk in this video.
Obviously, the persistent chat Discord offers was highly desirable for my community. Discord has persistent chat that can be read without joining any voice channels. It also (eventually) had an API for botting that was well beyond anything we had on Mumble or Teamspeak. These softwares still have some perks over discord, such as permissions granularity, nesting voice channels, and channel linking.
So what went wrong?
Our community has always had a dedicated core base all of these years that has not shrank, but based on what games we are regularly playing at the time (usually some kind of multiplayer game) some familiar faces would come and go. Some days our channels would be inflated with tons of people, some days its a ghost town. Fortunately the persistent chat gets us through the dark days of final exams and too-busy-for-fun times. The persistent chat is also a great downside. Discord functions more like a text-chat app first, and voice comms second. Before with Mumble and Teamspeak3 we had a web forum to meet the needs of persistent chat, but now the forum is gone and the chat is all that remains. I can now glance at my phone for five minutes and be caught up on the last several hours of happenings with our community. I no longer need to jump into voice comms and ask what is going on, even when our flavor of the month game is something PVP intensive with progression (for example, ARK) where we could lose much progress while offline. All I need to do now is read.
The same goes for everyone. It's all text chat, funny images, and bullshit.
That's not necessarily bad on it's own, but the text has downsized the importance of voice comms - which is a mistake
Discord also has an interface that lets you easily move between servers in the UI. They aren't really servers, as you can't self host. This gives the people running Discord absolute power over your privilege to participate. This is often abused and got so bad it picked up some (but not much) mainstream media attention.
Also worth mentioning, everything on Discord is monitored. There is no real privacy here. All it takes is a couple reports about the things you say or share and you could be cut off from your servers. As the recent furry porn controversy has shown what is worth banning for is not always aligned with morality or logic. Getting myself banned for harmless banter in a public server would torpedo a community like ours to the point where engaging in larger public servers is a risk. This was never a problem before Discord became the status quo. I'd argue that letting Discord become the status quo was a big mistake.
What should we do about it?
I've already majorly divested my interest and energy from Discord. I still look at it to talk to my friends, but I'm not trying to grow it and am mostly stalling for time. When the time comes and resources align I will probably host my Mumble server again. Hopefully I'll have all of that sorted out before the next big controversy strikes Discord, but there's a ton of other communities on Discord today that have no backup plan and I pity them.
If you're an admin of a Discord "server" and reading this then take a few minutes to consider what would you really do if Discord shut down tomorrow. What would happen to your community?