Your comment got me curious, and so just for kicks I just measured two 75 Ohm BNC cables that I had laying around; a 2 meter “RG-59/U 75 Ohm Coaxial” cable that came free with dCS, and a 1 meter Crystal Cable Diamond Digit Standard.
Here’s what I got (@ 10kHz and 100kHz respectively - the closest frequencies to 44.1kHz/48kHz that my meter would support).
RG-59/U; 88 Ohm / 85 Ohms
Crystal Cable; 76 Ohms / 78 Ohms
The cheapest RG-59/U goes for around $5, while the Crystal cable is about 100 times that. I’m not especially partial to Crystal Cable or anything, but clearly (some) cable manufacturers aren’t bluffing when they say 75 Ohms 