I am mostly confused by what the author thinks the selling point is. > I can’t describe what a breath of fresh air this is compared to how bad modern smartphone music and streaming apps have become. Well, I was hoping they would try to describe it, because personally, I would have to wear my most deeply shaded nostalgia glasses to think that MP3 player UX has ever been comparable to what Spotify offers nowadays. And…
In terms of UX, it's really hard to beat high fidelity audio and hardware buttons. Spotify is just an app. The real experience is the playback.
As for high fidelity audio, I doubt there is much between devices these days. I remember back when I was buying portable cassette and, later, CD players there did used to be a real noticeable difference between the audio fidelity of different brands (ironically with Sony often cashing in on their brand and than having worse fidelity than hardware from significantly cheaper competitors). However these days everyone is listening to lossy compression over bluetooth so there isn't really going to be much room for the host hardware to improve. As always, the headphones you use will make much more of an impact.