Every community has a fringe of crazies. I remember back when I first got into audio in high school, when I bought my first pair of >$10 headphones and suddenly I could hear details in music that weren't there before, and wondering how deep the rabbit hole went. I started reading audio forums and saw that most postings came from a small number of extremely active posters that made absurd, hyperbolic claims. There's a product review that has since become a meme, about some ridiculous $1000 RCA cables, how they sounded "smoky" and "danceable". I read that when it was first posted and felt disgusted. Then the moderators of the forum I read most often announced that any discussion of double-blind testing was banned and anyone who discussed it would immediately be banned. I deleted my account on that forum. What a disappointment. But the fact that fringe crazies exist doesn't mean the subject is all a joke. Car tuning is a legitimate hobby, even though I have idiot cousins who will physically assault anyone who questions the purpose of their undercarriage neon lights. And there is a difference between junk audio equipment and good audio equipment, even though there is also plenty of snake oil under the label "audiophile".
There used to be Monster audio cables that cost thousands. The Amazon reviews were hysterical. I can’t find it anymore, but this one has funny reviews for a $1500 HDMI adapter:
The reason you don't see Monster so much is the death of big box retail.
Monster's pitch to TV/electronic retailers in the early 2000s was that there was basically next to no profit margin on TVs themselves, so instead you could sell the customer a bunch of extremely high margin accessories to go with it.
This worked well in the early 2000s, because myths like "you should spend 10 percent of the cost of your AV setup on interconnects and cables" were still widely believed, and TVs still expensive enough that 10 percent was often a pretty big spend relative to today.
I worked for a major big box electronic retailer at the hight of the Monster cable era, you would not believe the pressures that were applied to sales people to include Monster accessories with every TV. It was quite common for the profit on the Monster accessories to exceed what little was made on the television being sold, and margins on almost all Monster products exceeded 50 percent. I used to wince every time I sold a 300 dollar set of component video cables.
