True. But as an audio engineer I have to say, that just because audiophiles are naive and gullible, doesn't mean there are no other, real, physical aspects that affect actual sound and reproducability.

Same for Espresso. A PID that keeps the brewing temperature steady is superior to a thermostat where the temperature ramps up and down constantly and your brewing temperature depends on experience or luck (people who know their machine would call this "temperature surfing" because you will have to wait for the thermostat to switch on). To which degree brewing temperature affects the result can be discussed, but this could be tested quite easily.

So if you are a coffee afficionado, the number one reason you would like to have a PID is probably convenience. One variable less to care about if you wanna get reproducably (good) results.

I'd also prefer the faders of my mixing desk to keep their levels where I set them instead of fluctuating around.