To All Cable Deniers, 1 Very Simple Question.

Can the OP hear the difference between the copper content in the plug pins?  Yea or nay.

Can the OP hear the fuse holders in his presumably very expensive (because you get what you pay for!), elevated high-end audio gear? Those are made of garden-variety steel (to snap security onto the fuse).

What about the inexpensive ribbon cables and IDC connectors, same as those in lowly PCs, can he hear them?

Or all the discrete components inside said audio gear - the resistors, caps, semiconductors - the vast, vast majority of which have ferrous alloy leads, such that you can pick up any transistor or diode with a small magnet. O the horror! Surely OP can hear that, can he?

It’s always hilarious to watch self-appointed Audiophiles pontificate about infinitesimal differences in things they can see, such as wall receptacles or cable elevators, while being completely oblivious of the far worse transgressions that lurk inside their gear. Out of sight, out of Golden Ear?

To jump in re the Ohno casting of wire, it’s not the resistance variation that matters, it’s the effect of grain boundaries on impedance that matters, as it varies with frequency and affects phasing. Our ears are exquisitely sensitive to phasing with frequency.

"Result: the too oft-repeated cable debate wars. So it’s up to each individual to face the intransigence that each cohort has absolutely NIL chance of EVER convincing the other side to change their mind."
I agree with this completely. The problem is that the group that denies that cables make a difference seem to think it is their mission in life to "educate" the others, often, in the case of one site, with bile and venom attached. Leave people alone and let them make up their own minds. 
"I have on the other hand had experiences with friends who are cable pilled and they have let me borrow their cables and they even set it up with my system and I was totally blindfolded and I came out of the experiment more staunch in my doubt of cables doing anything"
Well there you go. I have the exact opposite experience, also in blind testing,  and while I agree that other issues such as rooms, speaker placement etc are more important, I have definitely heard some cables making a distinct difference.

In answer to the Op’s question, I do not know if the % of copper makes a difference, but I deffinitely DO know that some cables improve the sound, and these are by far not necessarily the most expensive cables.

@ devinplombier

"Can the OP hear the fuse holders in his presumably very expensive (because you get what you pay for!), elevated high-end audio gear?"

This is a VERY silly response that adds nothing to the OP and is plainly a poor attempt at deflection. Here is a perfect example of someone behaving childishly in at attempt to prove their viewpoint. This is precisely the behaviour that is prevalent in some other fora.