A quick trip around audiophile companies should quickly disabuse you of the notion that high sales implies any kind of worth to a product. There are several companies making lots of money on selling gold HDMI, ethernet etc cables "to improve sound quality", and plenty of rubes buying them and "hearing the difference".
Real Hi-Fi companies like Sennheiser and Bose make far more money than people selling gold HDMI cables. And they've been making much more money for decades and will continue to make money for decades.
