the quality can only get so good with stereo lol
for headphones what the forget are you expecting
stereo is literally the realistic cap for speakers on headphones
on top of that you're talking about loving quality
have you ever used a pair of $200 non-beats headphones then used a $60-70 pair? the difference is loving night and day.
from infinitely superior build quality (one side
not going out on you in about shortly after a year but instead actually being built like tanks)
to clarity and superior choice of preferences in sound type (some people don't like so much bass, that's why sennheiser exists among other things)
this also translates over into ear buds too, it's not limited to headphones, and they're all stereo too.
for bonus points, people think no headphone jack is gonna be the standard despite being hated by basically everyone and all the companies are taking the ever-living piss out of apple for it.