In addition to that, there is insurmountable evidence of different biases affecting human perception. We also know that there is clear monetary motivation for manufacturers, dealers and magazines to talk about these mysterious, non-measurable differences. We know, that "serious" hobbyists want so very hard that their favorite pastime will never be "solved" and there would be clearly definable criteria for the level of seriousness of ones hobbyism such as money spent on gimmicks or claimed ability to hear difference between power cords.In over half a century of the existence of faith-based audio, no-one has ever demonstrated the audibility of anything not trivially measurable. Not once. Ever. This despite constant claims of audible differences where none exist and a niche industry catering to this nonsense.
So we have pretty much nothing going for unmeasurable things affecting sound and vast amounts of facts against it. There will never be final evidence about non-existence of unmeasurable variables, but the case against them is so strong that it's almost insulting to hear people still demanding others to take them seriously and avoid criticism.