Apple for some reason hasn’t implemented that feature, and it boggles the mind. Say I’m playing music on my iPhone and I try playing a track on my mac, it doesn’t ask me on which device to play, hell, it doesn’t even stop playing on my iPhone to start on my mac, it just puts an ugly warning in the middle of the screen saying something like “stop playing on your iPhone to listen to the song on this device”.
They have this feature, it is called Hand-off I think. It works between iPhones and HomePods. Additionally there’s “control other devices”, which allows controlling the music played on other devices. That is between most Apple device categories, although I’m unsure about Mac support for it.
I have used AM since launch and don’t understand what you’re complaining about exactly. I have never, not once, seen a message telling me to stop playing on one device to play on another with AM. Spotify otoh is super strict with licensing and does that. Why wouldn’t you want to be able to play 2 different streams in 2 different places?
I have my AM on my Sonos, my phone, my ATV, and my dad’s Sonos and have never seen a message that it’s playing elsewhere. With Spotify my setup absolutely would be impossible using the same account.
I personally don’t want the Spotify style playback features; keep them out of my AM please.
Edit: I forgot you can also now share a queue via Apple Music using airplay, even if others at the party don’t have an account.
It’s actually insane to me.