Of course AM radio is affected by unshielded Ethernet wires. This quite normal observation does not mean that in corollary the Ethernet signal has all kinds of digital static from the radio. Digital signals are extremely robust and there are error detection methodolgies to reject and retransmit packets of data in the event of interruption or data Tx collision from multiple devices (to the point of a hot swap of cable).
The SNR of PAM 16 encoding is 30dB. I don't hear anyone talking about that and how it affects audio output.

