Actually, I went through all of that decades ago back in Nashville, when the whole "super-premium wire" thing got up to steam. Like a lot of other engineers down there, I did those A/B tests...and like a lot of other engineers down there, I didn't see a qualitative difference that would translate into something that would justify the prices. The problem is this: no matter how high-end your own stuff is, what you're creating will be pumped through lowest-common-denominator playback gear 99% of the time. So if you get a small incremental benefit, this then gets wiped out at the consumer end, or when it gets uploaded to a content aggregator that uses mediocre compression algorithms.
But with speaker cables, there IS a major difference that you gain from stepping up your wire gauges, having a higher amount of conductors in the cable, etc. Big wire = less resistance, which lets your amp loaf a little better, which means it's not being overtaxed by big transients. And lots of little conductors in the wire means that the higher frequencies have more "skin" to move along, since "skin effect" is gradually more important the higher you go in frequency. And this one is something you DO benefit from, since monitor clarity is critical to knowing what you're doing. But there's a BIG difference between a line level or synth level signal and the output of a power amp...higher voltages, more current, etc, so reducing the resistance has a payoff at the amplifier levels, but you lose some of that benefit at lower signal levels as you're not trying to pump a massive signal through a tiny wire there.
So while I do advocate cheaper cables for line level signals, I use 14 and 12ga fine-stranded speaker lines here, with the gauge depending on the amp power (the Crest FA601 gets the 12s...it has a VERY high slewing rate, and clearly prefers driving a load with the bigger conductors). No voodoo or hype there, though...just good ol' basic EE at work.