In a perfect world, there would be the recommended mix, and then the apps (Netflix, Hulu, etc) would let you adjust the faders the way you can with EQ. Instead of one stream of sound, you can balance the voice/music/fx by yourself. Hell, throw EQ on each of those channels. Late at night and you don't want to bother the neighbors? Let me turn down the bass on the FX and Music channels. Also let me just turn down FX and Music channels in general because I can't fucking hear what the actors are saying.

Edit: I was talking to my wife about this subject and she was like "yeah, I can do this on my Peloton. Adjust the voice vs music"

So yeah. The technology exists. It may not be retroactive. Like movies and shows already made won't have the option (but vocal isolation plugins have come a long way). But we have the technology and bandwidth to do it moving forward.