The aspects you mention mostly make things easier for the developer side, not for the user side, which get only the indirect advantage of a more feature rich app.
If you want to do things properly, you hire separate teams who do native development for each platform, or you hire one Qt team for desktop and two teams for the two app platforms. Of course that's expensive, but again developer vs user side. That's what I mean by cutting corners.
And regarding electron there are different kinds of apps performance wise, like Atom vs VS Code. Discord is more on the Atom side of things, sadly.
Discord is also so big, that interested people develop lean third party clients for it. It's possible, but Discord rather bans them and forces users on the worse electron/web alternative.
If you want to do things properly, you hire separate teams who do native development for each platform, or you hire one Qt team for desktop and two teams for the two app platforms. Of course that's expensive, but again developer vs user side. That's what I mean by cutting corners.
And regarding electron there are different kinds of apps performance wise, like Atom vs VS Code. Discord is more on the Atom side of things, sadly.
Discord is also so big, that interested people develop lean third party clients for it. It's possible, but Discord rather bans them and forces users on the worse electron/web alternative.