You’re missing the point.
WiiM, Bluesound, Sonos, and Cambridge Audio are closed systems, users can’t access or modify the embedded software, so the risk of code leaks is minimal.
Volumio, on the other hand, is open source. That means anyone can inspect or alter the system, increasing potential exposure.
To mitigate this, Volumio built a secure, cloud-based backbone for authentication and security, an approach validated by both Tidal and Qobuz.
So the real question is: why is Spotify still resisting?