This seems like a moot point to me though. In one scenario, you have a 3.5mm cable from headphone to phone. In the other scenario you have a USB charging cable

This seems like a moot point to me though. In one scenario, you have a 3.5mm cable from headphone to phone. In the other scenario you have a USB charging cable going from headphone to phone (which you can keep connected 24/7 if you really don't want to worry about draining it). So if the quality problem is solved, what's the difference?