Calls on AirPods don’t sound worse to me than on the phone speakers, I don’t think the AirPods noticeably decrease the quality compared to the stuff happening on the phone network.

"The phone network"? As in the usually 8 kHz to 16 kHz quality call?

Of course that sounds like a tin can either way, it's coming in as a tin can! People here are talking about modern VoIP calls (Teams/Slack/Discord/Zoom/etc) which have a snowball's chance in hell of sounding decent in the first place.