Agree that science doesn't have all the answers but the psychological need to believe in an accepted expert, say a doctor, is very strong and can easily sway our judgement. In fact true science is about questioning, not ramming 'facts' down everyone's throats. OTOH have you ever done (or at least read of) a double blind comparison of speaker wire with a panel of recognized golden ear experts with really good speakers/room?
Years ago I was at a local audio meeting where we compared (certainly nothing scientific) two $1,000 USD pairs of speaker cables that couldn't have been more different in design (and sound). One looked like a silver garden hose, the other a nearly invisibly thin wire in clear ribbon sheathes. Science would predict what we heard, the thin one lacked bass response. But that lack of bass revealed greater clarity of the higher frequencies. That lack of any part of the frequency spectrum (a very basic premise for accurate sound reproduction IMO) removes it from consideration as 'high-end', period.
Yes, everything in the audio system can affect the sound. My argument against boutique external wires is to ask what wire is used inside each component of each piece of gear (probably several types and certainly of much lesser quality) and how that limits the final sound. And of course that sort of concern can be extended to whatever aspect of the production/reproduction chain you choose. Fixating on one small piece of the pie, like UPOCC, represents the kind of logic that feeds audio nervosa and the home audio industry.
