@nonoise I don’t know to laugh out loud or cry at your level of ignorance, but first, I am not trying to offend anyone.
Second, what happened with your analogy with cable tv vs Blu-ray? Facts didn’t line up with your world view?
cables do make a difference, to a point, however, for Ethernet, a base cable provides adequate performance for all the protocols above, and there are many, to function properly. And that is what matters. The whole stack of protocols include numerous error detection and correction mechanisms, Ethernet specifically is balanced and includes common mode noise rejection. I get it, when you don’t understand any of it, it is easy to just throw money at it, and then tell yourself it made a difference.
I have of course tried it, and products like Etherregen, and there is no theoretical or practical difference in sound.