However, if I were Spotify, I wouldn't be too concerned about this particular problem. Apple Music and Apple Podcasts come preinstalled on every iPhone, so Spotify effectively lost the discoverability battle before the user even got to the App Store.

By contrast, I'd be quite concerned that Apple is outright preventing me from making my app as good as their first party offerings. Spotify will not ever be able to open Podcast links shared from Safari, or fully integrate into Siri.