I think there's very few people who would fit in to the internet speed range of "capable of streaming music consistently enough to prefer that over downloading" and "downloads slowly".
If my friend tells me to check out a song or an album, I type in the first word or two of that song or album into spotify and I'm listening to it instantly, whether I'm on my phone or my computer.
Do you really think there's no difference there? If you get a text from a friend saying check out this song and you're out and about on your phone, are you really saying that somehow downloading an mp3 to your phone is as easy as spotify?
Finding and downloading mp3's isn't a problem.