We need to look at the whole system. Cable impedance is designed to 75 ohm to match everything else in the signal path. However, everyone knows nothing will be perfect, so it comes down to how close is the actual impedance to 75 ohm. How about the connectors, trace of PC board, etc. What matters is at the point where the clock information is recovered from the signal. If it is not exactly 44.1kHz, there is jitter and it causes distortion to the audio signal. Therefore, cable quality matters if everything else in the system closely matches to 75 ohm. If by accident, everything matches to 70 ohm, it will be good too, but chance for that to happen is very small.
Therefore, professional studio use master clock such that only the 1 and 0s are decoded from incoming signal and not the clock information. In that case, jitter can be minimized to just between the DAC and master clock generator. Then most effect from the cable can be eliminated. A few high end decoder manufacturers adopt this setup like Esoteric and DCS for home use. It is a much more expensive solution, but it works.
Cheers and enjoy music
Therefore, professional studio use master clock such that only the 1 and 0s are decoded from incoming signal and not the clock information. In that case, jitter can be minimized to just between the DAC and master clock generator. Then most effect from the cable can be eliminated. A few high end decoder manufacturers adopt this setup like Esoteric and DCS for home use. It is a much more expensive solution, but it works.
Cheers and enjoy music