It’s mostly C.
And Gnome is far from the only desktop that uses JS, KDE Plasma, for example, also uses a lot of JavaScript.
It’s weird when people bash Gnome for using JS, when practically everybody else uses it a lot too. Shows that they’re just regurgitating “Gnome = bad!!!” nonsense.
We get it, you think disliking Gnome is a quirky, edgy personality trait.
Mostly C because you need to type more C code to do the same with JavaScript, so I suppose most of the logics are using JavaScript. Plasma desktop has 2% JavaScript (https://invent.kde.org/plasma/plasma-desktop), it’s not comparable. 🙂
There’s a lot more to your UX than just the Plasma desktop. And you’re also trying to pass off Gnome’s shell as being Gnome desktop. Pretty disingenuous.
But at least the desktop itself isn’t using JavaScript that much like Gnome do. Show me the repo with the % to see what are you referring.