VoLTE with fancy compression didn't make audio quality better, it just freed up bandwidth for carriers to cram more channels in. This has repeated for every single "improvement" in VoIP technology over its ~40 year history, the tradeoff always goes in the direction of making more money instead of offering better service.
If you're calling within the same carrier with "HD voice", AMR-WB at 12.65kbps scores a higher MOS than old-school G.711 64kbps PCM (and is more pleasing in some ways that the MOS doesn't capture).
Sure, if they'd just give us another couple dang kilobits/second it'd be way better still, but...
At this point, the bandwidth used for voice is pretty much irrelevant from a cellular capacity planning point of view-- people use >5GB/month on average and 24/7 12kbps calling is less than 5GB/month.
> VoLTE with fancy compression didn't make audio quality better, it just freed up bandwidth for carriers to cram more channels in.
Not just that, it’s also used for additional carrier lock-in!
(In Canada, carriers were barred from selling carrier-locked phones some years ago, but since VoLTE, they don’t support VoLTE functionality on any phones that haven’t been certified for use on their network, which is limited, in practice, to phone models that they sell themselves. Normally this means you fallback to 3G for calling, unless you happen to be roaming with a carrier/country where 3G service has been dropped, in which case you simply don’t get any voice service.)
