I think it runs on every A9 (iPhone 6S) powered phone and tablet or newer. So more or less every iOS device sold since 2015/2016.
Yeah and fragmentation in Android versions is pretty bad. Also the quality of the underlying hardware might be not as consistent as in iOS devices. It relies on a lot of sensors to get it right, not just raw CPU power and a nice camera.
iOS has had a ton of effort put into its audio stack - it was an iPod replacement as well as a phone. Remember when the app was still called iPod?
iPod users wouldn't have taken the iPhone as seriously if Apple hadn't put in the work to make audio a first-class citizen. Android doesn't have that pedigree/baggage so it's never been as important.
Yeah and fragmentation in Android versions is pretty bad. Also the quality of the underlying hardware might be not as consistent as in iOS devices. It relies on a lot of sensors to get it right, not just raw CPU power and a nice camera.