I just don't get streaming services. How are they different than listening to the radio or to on-line radio? Or indeed how do they differ from the user-generated playlists that we used to see in iTunes? If I like a song I buy it. I don't want to rent songs.
1) They customize your listening preferences down to specific songs you don't want to hear. Also better music discovery since your preferences are matched.
2) In some, you can curate your own albums.
3) Fewer ads, or when used with some devices or if you pay, no ads.
4) No annoying DJs with their insipid comments or long winded stories of how drunk they got last night.