Some decade, bluetooth will get there.

While it's improved a great deal, there remains a gap.

Noise cancellation is getting pretty good.

It is not necessarily a protocol/technology issue, more a cultural one. Most people are just not looking at quality first and will buy whatever is cheap, loud and has the form factor they want. Music is so compressed nowadays that they don't even hear a difference between crappy and better quality speakers.

Very plausible. Until they hear the same song much clearer and wonder what the difference was, as long as they enjoy music :)