So there's iTunes (2001-2019, but arguably renamed to Apple Music, so not actually dead), and Ping (2010-2012), the latter of which had approximately three users.
Like for like, Google Play Music (2011-2020) isn't quite as long-lasting, but more to the point, I'm not sure Apple has simultaneously maintained two competing services before ultimately canceling one.
Then the GP commenter mentioned "chat services," which makes the position unassailable. Google seems to have launched and folder a dozen or two chat services over time[1].
You can make and receive FaceTime calls from any recent Apple device to any recent Apple device (e.g. Mac to iPhone) which is nice, but FaceTime’s real advantage is call quality. It’s noticeably more clear and seems to handle poor/unstable connections much better.
I can FaceTime with people halfway around the world with more clarity than I can talk to someone on the same WiFi network using WhatsApp.
The blue and green chat bubbles are the sender’s chat bubbles, not the receiver’s. So it’s the iPhone user with the colored bubbles, non-iPhone receives and iPhone receivers are white/gray.
It has a couple of really good use cases as it works on non-phones (macs and ipads). Little kids and some older people don’t have phones. I like the bigger screen for non-casual video calls.
Also, I was on a project with a colleague who had a poor internet connection and we found FT worked better than zoom. FT video quality seems to be the best of the services I’ve used but personally I don’t care about this part much.
I wouldn’t call these “killer features” but they are enough, with the integration into address book etc, to make it flourish.
