I guess we're picking at nits now, but it's less about Apple 'putting restrictions' on such things and more about Apple being slow and inconsistent on implementing and exposing AirPlay 2 functions in their products (and also getting the right support into their SDKs).  I was surprised that the Apple TV 4K, with it's System Settings ability to configure whole home listening, also had an app-level requirement to make AirPlay2 work (though perhaps it was necessary only to recompile using AirPlay2-savvy libraries... don't know.).  At the time I noticed the issue, the Amazon Music app and others on Apple TV played music everywhere just fine (Spotify and Pandora were notably slow). As far as I know, MacOS has never had the ability to set your Sound Output to multiple speakers simultaneously - that's more of a 'whole home' media entertainment thing - hence the app-level AirPlay hack in [MacOS] Apple Music. ... View more