There’s certainly woo and outright fraud in audio. But there’s also attention to detail.
Professional studio engineers will spend $3000 on a high-precision digital clock for their DACs because it makes a clearly audible difference.
Software people don’t understand that human hearing, and human sensitivity to timbre and distortion, is spectacularly non-linear.
Hearing isn’t a linear counting device with x volume levels. It’s an incredibly sophisticated neural network that performs real time classification and source separation based on spatial and ambient cues, spectral analysis, predictive modelling, and entropy estimation.
Some people’s brains and ears are better at all of this than others. Those people can hear things other people can’t.
In music, someone with a trained ear can name the notes in a chord. Someone with exceptional skill can name the notes in a random cluster of pitches on the lowest octave of a piano.
Audio quality has analogous levels of sensitivity. People who have neither shouldn’t be telling people who do what they can and can’t perceive.