With Discord in browser, you lose Krisp, RPC ipc socket support (aRPC might work, no clue), and from what I remember screensharing only worked with browser tab capture.
Element will eat your RAM no matter where it’s running. You could add it as a Nextcloud app to triple your RAM usage! Woo
And you can’t run Steam games without the Steam client running. That’s how their DRM works. (Unless you use the goldberg steam emulator, which is a whole another thing to talk about)