I'm not the author, just agree with the basic argument of the article, if maybe not every detail in it.

The thing is just the incredible ease of use. The easy with which you can join a server and then drop into any text or voice chat you feel like.

There are probably programms that technically replicate the feature set, but I haven't used anything that feels as effortless as discord does. And I can't even pinpoint why exactly that is.