It isn't unique, it provides text, voice and video chatting. These are not new services to the world of technology.

What makes Discord stand apart is that they require that your chats, calls and streams are not private and, in exchange for people giving up their private data the users only have to install one piece of software instead of two. It is like a company giving people a 'free' phone as long as they or their advertisers can listen into the calls, read the texts and look at the videos on the phone.

The only thing that Discord does is to package the software in such a way that you can't access it until you give them information about you and then they gate features behind you identifying yourself with a credit card and a phone number.