@Gargron That may be true for embedded systems like car music players or even entry-level HiFi equipment, that is still 20+ years behind in terms of format support… But that's hardly true for any non-embedded and up-to-date software…
OGG is not Opus (which is actually still not-so-widely supported), and has been around since the ≃2000s… There's no sane reason to not support it "because it's not supported elsewhere"…
@devnull @lienrag Ogg is not supported on Safari on iOS:
https://caniuse.com/ogg-vorbis