Evidence? It uses lossy audio codecs. Some are good, and some are less good, but they're all lossy. The quality loss happens before the bits hit the radio. That part is fine, as you note. "Oxygen-free copper", regardless of whether it's beneficial, is generally used for analog signals, which isn't moving bits at all.

Bluetooth also introduces latency. It might be ok for mixing, but it's completely unusable for recording applications.