[lstamour]

Any app can save documents to local storage. As an example, I've 90GB of Spotify music on my phone, as I told it to download the entire "Liked songs" playlist. Google Play Music and YouTube Music also download to the phone. So no, you aren't forced to use Apple Music. You can even change Siri to use Spotify as a default in limited circumstances. It's not an iOS restriction the way independent browser implementations are restricted or how you can't set a default Mail app or Web Browser. There isn't even an iTunes app for syncing any more, so it's hard to argue that Apple has a giant advantage over third-parties ... except in how Apple gets a 30% cut of in-app subscriptions from third-parties, of course. And how asking Siri "What song is this?" always takes you to iTunes to buy it.