I think it’d be a great idea to have a separate volume slider for the commentators on streams and the actual game itself, or music they’re playing. I’m not sure how this would be set up between client and user, but it would be amazing. Sometimes I run into streams where I want to hear the in-game volume more clearly, or I’ll run into a stream where the announcer or streamer is really obnoxious and I just want to mute them, but still hear the in-game volume.
This is a commonly requested feature. Unfortunately doing so would not be realistic with current player tech that we rely on.