A digital signal is a different beast than an analog one. A single analog cable can carry only one signal or channel of information. A digital cable is capable of carrying multiple channels of audio or video due to the fact that all that is being conveyed is a complex series of "ones" and "zeros". Analog signals gradually lose voltage over long cable runs, and a little bit of loss can be tolerated. Digital signals are all-or-nothing; at a certain point a loss of voltage will equal a completely lost signal.
You could use a standard RCA terminated interconnect as a digital coax cable, but it is not a good idea. Digital signals are subject to a phenomenon known as jitter which affects the timing of the delivery of these 1s and 0s. In cables, jitter is caused by noise and interference, so a good digital coax cable needs full shielding and high-quality connectors. Digital signals quickly suffer losses at an impedance different than the 75 ohm standard, so cables made to tight tolerances are best. These best digital coaxial cables in 2022 were selected based on shielding, connectors, and overall manufacturing quality and value.