Spotify is testing a feature that would allow users to upload their own tracks into their personal Spotify library. Apple Music already integrates tracks stored on an iPhone with its streaming music service.
Spotify is testing "Import your music" directly from your Android device pic.twitter.com/Nx28gdI4mR— Jane Manchun Wong (@wongmjane) November 29, 2018
If launched, the addition would make Spotify a more useful music service for hard core music fans. As comprehensive as Spotify's 40 million track library is, it's still usually missing tracks that the true fan wants to listen to. Bootlegs and that track you recorded live on your cell are never going to be a part of the official Spotify catalog.
But given Apple's closed ecosystem, it's hard to imagine Spotify's import feature coming to iOS devices.