My first aftermarket interconnect was bought around 1978 and made by Audioquest as I recall. I remember being undrwhelmed by it's performance, especially at the price I paid for it.
Next was a Van Den Hul speaker cable circa 1983 which again wasn't cheap and to be honest the sonic 'improvement' didn't bowl me over either.
From that, one could gather that I :-
a) Didn't have a good enough system
b) My hearing was suspect
c) The cables were more marketing hype than substance
My instincts at the time were favouring c) and as time went on the legend of cable products were based more on folklore and wishful thinking than actual performance, not to mention the price tags of these baubles, so I started making my own for considerably less money and greater sonic benefits.
Oddly enough, it wasn't until I started playing around with mains cables that the light suddenly came on that I wasn't putting in a sooper dooper cable, but actually taking the inadequate cheapo cables OUT and putting something less inadequate in. The better the cable spec and build quality, the less inadequate it was, culminating in the realisation that no cable is ever perfect so all our choices rest between those two extremes.