Why do so many people love Discord?

I don't know. I vastly prefer IRC. Maybe it's because using discord takes virtually zero skill and a lot of non-techy chatrooms are on Discord? Most Discord people I know are not aware of IRC, Mumble, or other (older) chat softwares...

Like any platform, there are pros and cons. But there are a few key positive features I like about Discord. Most notably the ease in which you can link to a group and people can join automatically in contrast to how difficult it is to get up and running in a new Slack group. This is a huge plus in my opinion. It removed the need for a complicated sign up process and for you to quickly engage with a community or remove yourself if that community isn't quite what you are looking for.

I've poked around Discord a bit, and I just don't see the attraction. As another commentor said, maybe it's the audio channels. But I can't think of a reason I would ever personally want to tune in to audio rather than reading information, it's just faster to read than to listen to someone 'ummm' their way through a thought.

Of course, I still have a hard time using YouTube as a learning resource because of my preference for reading, so I'm probably an outlier here.

Discord is a much more community focused, external communication platform compared to Slack.

Slack is priced on per person economics, while Discord is oriented on individual usage. People can choose to pay a subscription to unlock better emojis and other server privileges, which allows Discord communities without any budget to have thousands of users.

I agree with you. I also find it difficult to use, not ergonomic.

Maybe is it because they have the audio channels. But I find the audio quality to be bad!

"Discord is proprietary."

Aren't Twitter, Slack, and other platforms also proprietary?