there is no signal degradation like used to happen with analog RCA cables. You are now just moving 1s and 0s and the signal is either on or off. There is no in-between
This is the common misunderstanding of audiophile and videophile on digital signal processing.
Short one
0 and 1 are at the application/middle layer of transportation of digital data. In the lowest layer : still analogue wave. It means if you intercept the signal what you will see is just analogue wave.
At the protocol layer where those analogue wave are converted to digital bits 0 or 1. Analogue wave in 0s and 1s out. ADC.
There are always 0.9, 0.8, 07, 1.1, 1.2 just you don't see it because all of us are talking about application/usage not how the data are transported.