When Apple introduced iTunes in 2001, it served one purpose: As a music jukebox app. Later that year, it added its most important feature: The ability to sync tracks with the just-introduced iPod.

I remember the days when I’d get a new CD, rip it to my iTunes library, connect my click-wheel iPod, and have the music sync in less than a minute. Ah, the good old days were so much better…. Now, ...