It's kind of funny in a way. Headphone 'quality' is a damn near religious crusade for some when it is also something that is extremely subject to a vast array of variables and for the most part people really don't know what the fuck they are talking about when they talk about sound quality. We talk about things like flat response or bass boosted or range but these terms are almost entirely meaningless in real world usage where perception is what ultimately makes or breaks whether you want to listen to a thing using something or something else.

You prime someone into thinking that such-and-such is really good or uncompromising or super high quality and they'll literally believe that they are hearing 'the difference' and there's essentially no way to unseat this because it's their experience.

Which isn't to say shitty headphones can be brilliant or brilliant headphones can be shitty but there is a huge amount of gray area throughout, is the point and almost always people who think they are being objective or exhaustively testing or blind comparing or whatever are compiling a combination of their biases and preferences along with the conditions they're approaching the thing, the music they've selected, their own taste in music, the amount of damage their hearing might have sustained, how fatigued they are, the environment they're in...etc...etc...etc.

Just so many variables and external factors but everyone, damn near everyone sits down and hears something and then goes "yep! I'm an expert now because I know what I heard and X is 'better' than Y"

But you can so easily manipulate that. The exact same pair of headphones can sound great and terrible in the same day with nothing changing but how tired the person using them is.

Meanwhile, the punchline is that for the most part audio technology has improved enough that tiny drivers are outputting pretty impressive stuff for general listening usage regardless. Sound quality has already been effectively 'solved' for the majority of listeners with everything else being mostly a preference of fit, feel, brand association, comfort...etc. (not that there aren't any shitty headphones out there, there still are of course but the entry threshold into 'good' has dropped significantly)