It works with several streaming providers. The API is opt in though (Coordinated Media Playback), so the providers need to implement some hooks to make it work

It works with several streaming providers. The API is opt in though (Coordinated Media Playback), so the providers need to implement some hooks to make it work, meaning they've decided they have the rights. Notably, Netflix doesn't allow it, but Disney+, Huly and HBO Max do.