I don't think it is baked into the OS. For exemple, Now on Tap in AOSP is just an 'Assist API' . Any app can implement this system callback in order to enri

I don't think it is baked into the OS. For exemple, Now on Tap in AOSP is just an 'Assist API' . Any app can implement this system callback in order to enrich an Assist call and any developer can create an alternative to Now on Tap that will get the exact same data from the device. AFAIK, All the Google branded apps & Services are part of Play Services. Nothing prevents you doing what Amazon is doing and create a device from AOSP, don't include AOSP and replace it with your own services. IANAL, but it seems that the focus is on the fact that Play Services comes with a full suite of apps.