Depends on how you define locked down. Apple Music has been available on the Google Play store for years [1] and also supports listening in a web browser on any operating system [2]. I do agree Photos could use some cross-platform improvements.

[1] https://play.google.com/store/apps/details?id=com.apple.andr...

[2] https://support.apple.com/guide/music-web/welcome/web