I read this https://grapheneos.org/faq#hardware-identifiers on hardware identifiers like IMEI etc and I understand that non privileged apps can not access them.
What confuses me are two apps that I use that ask for the phone permission. Escpecially one of those apps doesn't work at all without phone permision and it doesn't work without Google Play either. The app and Google Play (services / framework) seem to communicate with each other with mutual consent.
Now I don't really understand what the phone permisson granted to a non privileged app can do. It shouldn't be able to access the hardware identifiers, not by itself not through Google Play.
But what information can the not privileged apps access when phone permission has been granted? My phone number? My calling logs? Would such an app be able to share this with Google, if the two apps communicate with each other?