Smartphone chargers had legitimate reason to change. Higher power, faster data, and we learned the hard way that micro usb and all the proprietary connectors before it were fundamentally physically flawed.
Audio hasn't changed at all in the last two centuries. An analog audio signal is fundamental physics and there's nothing to gain or change or improve in any meaningful sense. TRS/phono jacks likewise are just so brute force stupid and rugged that there was never a reason to change.
The connectors and interfaces never changed because the underlying signals never changed because there's nothing to change. Digial electronics on the other hand legitimately have gone through real and worthwhile changes, and been radically redefined many times in the last 60 years.
Audio hasn't changed at all in the last two centuries. An analog audio signal is fundamental physics and there's nothing to gain or change or improve in any meaningful sense. TRS/phono jacks likewise are just so brute force stupid and rugged that there was never a reason to change.
The connectors and interfaces never changed because the underlying signals never changed because there's nothing to change. Digial electronics on the other hand legitimately have gone through real and worthwhile changes, and been radically redefined many times in the last 60 years.