One of the things that (for me) makes this hobby continually engaging is the soft pursuit of chimera, wild hares, and with the occasional red herring thrown in. A bit of background: I am an Architecture/Fine Arts major who worked his way through an Ivy League institution working as an electrician, and whose first 'real' job out of college was as a machinist. After doing that for a few years, I could afford to work as towards becoming an architect - and that job, I was making in a month what I *cleared* in a week as a machinist. Which led me to construction, engineering school, and ultimately property management. Not a transistor or vacuum tube along the way, but always an appreciation for music and the means to reproduce it 'at home'. Cutting to the chase, my eyes (ears) were always bigger than my wallet, so I learned the hard way the art of salvage, repair and restoration of cast-offs, garage-sale and flea-market finds, dumpster dives and similar. Lots of smoke and smells along that route. I do not have a 'technician' or 'engineering' attitude towards the hobby, but curiosity in great quantity, even now.
Now 50+ years in the hobby, I have learned a lot. And I have learned a lot about what does, and emphatically, what does not make a difference. Examples include, but are not limited to:
Cables/wires/connectors: After a basic level of quality, both build and material, it makes no difference under most conditions and circumstances. So, a 50' run is different from a 4' run - and appropriate gauges and materials apply for that 50' that may not apply to the 4'.
Within the realm of capacitors, again after that basic quality control is met, and the appropriate materials are specified, a cap is a cap is a cap is a cap.
And so forth.
Transducers are the last frontier of audio - that which changes the one sort of impulse to another. Noise to electrical, electrical to noise, vibration to electrical and so forth.
Amplifiers, tube and solid-state are done-and-dusted.
Pre-amps, tube or solid-state are done-and-dusted.
Tuners, tube or solid-state are done-and-dusted.
CD players are done-and-dusted (Virginia, for the record, there are but so many chipsets out there, similarly for DACs).
There is an entire subset of the audio industry that puts little green LEDs underneath their tube equipment for effect. And charge handsomely for them.
There is an entire subset of the industry that will soak various bits and pieces in liquid nitrogen, and charge handsomely for that.
Little catenary towers.
$5,000 receptacle blocks.
Now, if the purchaser of said 'stuff' is made happy thereby, can afford it, and feels pleasure in ownership of same - I have no problem with that at all. But only if that purchaser was treated honestly, fairly, and transparently throughout the transaction.
Keep in mind that this hobby, at any level, is mostly for a tiny subset of the population, clearly less than 1% if even 1/10th of that. There is enough legacy equipment out there, at every level of quality, to maintain the hobby, probably very nearly forever.