Spotify Wants to Use iPhone Volume Buttons to Control Connected Devices, But Refuses to Support AirPlay, Which Would Solve the Problem

Spotify claims Apple may be violating the European Digital Markets Act (DMA) by discontinuing the technology that allows Spotify users to control the volume on their connected devices using iPhone's physical buttons. This issue affects iOS users streaming via Spotify Connect, who will now have to use the volume slider in the Spotify Connect menu to control the volume on connected devices. The problem does not affect users controlling volume on iOS Bluetooth or AirPlay sessions, nor Android users. The question arises as to who should decide the rules for how the hardware volume buttons work on iPhones and iPads - Apple or the European Commission?