Which is a really fair point. Because why waste time on this, when a user who cares about playing their own music can just open a browser tab or spotify/apple music/local/etc. app, and it will work literally in any game anywhere. And Playstation supports Spotify/Apple Music/local music playback during games natively, without any hacks or workarounds (like using the built-in web browser) as well. I assume Xbox has similar functionality, but I don’t have much experience with it.
The only games i’ve seen that allow (limited) in-game audio provider choice are those that have an in-game radio feature (older GTA games, Forza, etc.), so that the custom user music kinda works “in-universe” in those games.