Spotify also adds value to the iPhone, before the App Store it was pretty but kind of useless. Make them give both options, people can decide whether easy cancellation etc. is worth 30%, Apple can make up any losses it needs to continue the platform from the iPhone sales price (or they can charge for App Store access or whatever, we should make them allow third-party stores/sideloading regardless), people can then decide whether that platform is worth it over Android.

The iPhone before the App Store was exactly the same as all of the other phones on the market at the time, none of which were useless.

Wrong, Spotify's existence does not depend on Apple and their platform. Spotify works on all platforms.

Apple is rent-seeking by abusing their natural monopoly on app distribution on iOS platforms (their platform, their rules) which is leveraged to create a monopoly in IAP channels.