It supports services apple decided aren’t competing with Apple Music.
So, Apple's in the wrong because Spotify didn't add the Siri music API?
In 2020, Apple did a HomePod Siri music API, and some services, such as Pandora, have adopted it.
Unfortunately, Spotify, the biggest music streaming service, has still not implemented this
https://9to5mac.com/2023/09/21/ios-17-play-spotify-music-on-homepod/
It’s worth mentioning Apple has released a new API for music streaming apps allowing them to be controlled by Siri through a HomePod. However, Spotify, for whatever reason, has refused to implement the software into its app on iOS.
Like, I get it: the internet has a hate boner for Apple, and in a lot cases it's justified. But it's 100% on Spotify for this one.
YT Music
https://www.techradar.com/audio/audio-streaming/your-apple-homepod-finally-supports-youtube-music-heres-how-to-set-it-up
Tidal
https://9to5mac.com/2022/04/21/tidal-is-the-latest-music-streaming-service-to-add-siri-integration-heres-how-it-works/
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