I switched to Amazon Music and at the time the webapp looked pretty much just like mainstream Amazon: drab, white/orange/blue, simple. But dang, it was rock solid. I couldn't get it to error if I wanted to. I could leave the tab open for weeks and it'd play music on command without missing a beat. They have since redone the site to make it look more trendy and more Spotify-ish. This new skin brought bugs with it and it's not the reliable workhorse it used to be. It's still way better than Spotify though.
I am very sensitive to buggy software. And in my opinion, most software available today is just riddled with bugs. I completely switched away from Apple because of this for example. To me, this is the real tragedy of modern software. The bad UX, the dark patterns, the slowness, etc... None of this stuff bothers me all that much when it comes down to it. But bugs, bugs get me every time.