Apparently requested since 2004, according to gHacks[1], but the oldest entry in Bugzilla I could find was from 2014[2].
However, that entry does reference a post from mozillaZine from 2004[3].
Though it's not really a request, but an addon that made it possible to change keyboard shortcuts back then.
Though sometimes oxc complains about JSX in JS when running vite, but it still works fine.