Same story as with 4k video displays
The existing resolution/quality is perfectly adequate.
The quality of the content, not its reproduction, is so much more of an issue - it also cannot be solved by technical evolution. It is the creative, artistic aspect of the work. It requires different (i.e. artistic) skills, and ability. It also doesn't sell new hardware based on new technology - equipment from the last couple of decades is perfectly good enough.
If you are really looking at supposedly higher quality reproduction, you'll likely want a completely acoustically isolated and perfect listening room. You'll probably have to treat it as a clean room as any dust particles will play merry hell with the whole affair. And you'll spend your energy trying to discern whether it was a Northern or Central line tube that you think you could hear for 1.34 seconds after the 3 cymbal crash, rather than whether it was a jolly fine piece of music or spoken word or whatever.
Good original content, produced well, is what the consumers want. Not fancy technology.
Biting the hand that feeds IT
