So… a digital “cable” the wire part, not speaking on the connector, does not need carry but minimal voltages in a narrow range, but noise (interference) is of much higher concern because, as the signal is “low”, any interference is going to be “high” relative to the signal.
With a full spectrum, higher voltage signal, “analog”, the density and power of signal is higher and so the “interference” is vanishingly small (given the same interfering signal as above).
Increasing the signal value relative to the interference value is a different beast depending on what type of “information” and at what “strength” and “density” that signal is.
Analog signal carrying fat pipes with some shielding (impedance as low as possible) vs digital signal carrying thin “pipes” with heavier shielding with specific line impedances per specs for the transmitters and receivers depending on what they are doing.
which is why optical cable is superior as shielding that from anything that can interfere with the light stream in the cable is much easier than shielding “regular” signal from emf interference. (And the specifications for optical is a .. more dense… info stream)
also why interference coming in on the power input is of concern.. there is no information, so any interference signal that is picked up has an outsized influence on signal as that interfering signal becomes part of the base of the carrying wave produced in the audio stream.
at least that is my layman’s conceptual understanding.