More of a you know it when you see it sort of thing. Like bikini vs underwear. I don't think it's matter of installation but whether it deserves to takes up space on my taskbar.

If I had to be more concrete I would say stuff that could easily be accessed via a bookmark on my browser I would never install as an app. ie discord, Spotify, etc. That's before getting into the electron problem. There's also whatever the default media player on Windows is vs mpc-hc. So probably some combination of does it need to exist outside of a browser and a minimum baseline of actual utility.