Discord's main competitive advantages:

* Centralized identity, and participating in multiple communities at once: People sign up once, then navigate to whatever autonomous communities they choose quickly.

* No hosting requirement (good for ease of use): Want a new autonomous space? Create it! Boom! No installation, no hosting, no monetary cost.

* Video streaming: No other chat client does this easily. Not Mumble, Ventrilo, Teamspeak, or these chat programs.

If you want to defeat Discord, particularly in the gaming server arena, you need to make interacting with multiple servers better and you need screen/video streaming.