Agreed. But I hope you agree that all theorems start as speculation and my point is dismissing all speculation will lead science nowhere. My first example is the best, for over 20 years cosmetologists have found no proof of dark energy or matter but the current models of the universe still stand.
Not always, it can be the result of observation and possibly with some prevailing knowledge that is relevant. Thomas Edison utilized observation all too often, e.g. light bulb - lol.
To me the basics of Electrical Engineering and properties of materials such as Copper and Silver and how they are applied in Headphone cables is pretty basic. We are not talking about rocket science so if one can hear a difference, the question is why? IMO, we as humans make poor witness to our senses and are subject to subjectivity which in this topic is the source of much controversy.