If there was a bluetooth profile that was duplex and had acceptable audio playback I would consider paying for a good pair, again. But mSBC, being the best available, is mono only and sounds like a 90s phone call.

Bluetooth Low Energy Audio with the LC3 codec should be finally able to do it. And some of the newer headphones support that. In theory. How good this works in practice, I don't know, manufacturers aren't even advertising proper duplex, probably because they would have to admit that the old mechanism is just crap.

That's actually exciting. I'll keep an eye out for that for sure. And I agree I think this is not talked about because we would collectively agree that what we have is shit.