I generally go with a desktop app eventually because it ends up doing something that I just can't do in the browser. In the case of discord, I can never get voice to work well over the browser. Maybe it has to do with all those fancy acceleration options not being exposed via a web browser, or maybe not and its something else.

I do stick with webapps when I'm a device other than my main desktop because I'm often too lazy to install something. The exception is mobile where mobile browsers and sites almost always piss me off to the point of installing a native app. I also will stick to the web app if the desktop app offers no advantage.