Forget cables as snakeoil. There's a new snake King in town.

I had to chime in on this one. I usually don’t. 
Give a chef, or even just ten regular cooks 10 ingredients and the dishes they prepare will all taste and look different!  Ten different amplifier designers using basic amplifier technology, and implementing the parts in different ways will do the same thing.  It will sound different, how could it not?  
I’ve been doing this for over 30 years,  they sound different!  
Speakers sound different!

I realize that people hear what they hear, which is really the best example that things sound different. I don’t see how anyone can’t dispute that?
 

When evaluating what you read, one must always consider the source.

@jderson

I think your analogy is pretty good about chefs and how they tweak thing.   But it does beg the question as to whether we want perfection or just what’s to our taste.

Ultimately the limit is the recording.  And no cable, amplifier, speaker or DAC can be any better than the recording itself.  They may change the sound of the recording, but they can’t fix it.

As to your last point, While you can measure a lot about sound, you can't measure what you hear, so it leads to a lot of subjectivity (and arguments).   I have a setup that I love, but there are some days when it doesn't sound quite right.  Nothing has really changed except my brain.  So that's why I'd rather spend money on music rather than trying to change phantoms in my equipment.

If only this was the case. There would be no need to purchase any amp over $1000. Anyone who has been messing around with audio for a while knows, almost everything makes a difference. 

As someone who repairs vintage amps, they all sound different. Say I have 2 identical amps. I recap one with brand X caps, the other with brand Y caps. Guess what? They will sound different!  Even changing a couple electrolyte caps, to a film caps will change how the amp sounds. 

Yes, every amp will sound different. You can even put a scope on the output and they have different sign waves. 

Anyone with a Class D amp knows you can change the sound of the amp with just swapping out the power supply. People who have measured the output of the amps with different power supplies have recorded differences. 

These are facts based with measuring before and after, plus using ears that can also measure the difference. Think is someone can't understand measurements, or have good ears, then more power to them, as they can get cheap $100 class d amps and be happy. 

I agree tomrk ! 
 

I'm just addressing the fact that things definitely sound different!  I’m not even sure perfection is attainable?  Obviously perfection is different for everyone!