I suggest some believers in magic here do a little reading on human objectivity, or lack there-of. More productive than snide insulting remarks. Human senses are not and never have been objective. This is why first person witness is the lowest form of legal evidence. We hear and see what we want to see.
Look at dates of publications. USB mode ONE is not Mode TWO. DAC's from 2013 are not the same as even the cheapest today. Much has been learned, much has been applied. Clocking WAS a problem as it was host based. It is not now. NOPE, GONE. Noise injected by ground, shield or 5V can now be totally eliminated. Cheap.
I do not sell either cheap or expensive cables. I am not trying to defend my ego for being scammed. I am not a total measurement is all. I do listen. But I also understand how these transfer layers work and only which to help those who do not have the technical background. They don't teach digital communications in medical or business school. Seems they no longer teach logical thinking and arguments either.