

GrapheneOS supports this type of security checking outside of Google’s Play Integrity API but app devs have to enable it. The Graphene devs encourage leaving one star reviews, emailing support, and linking this page: https://grapheneos.org/articles/attestation-compatibility-guide
Maybe because… automatically recording calls is literally illegal in some places around the world? It should probably be user choice to opt in to that so it wouldn’t be on by default. And then, if you have it on while travelling, you could forget and break the law when going through a jurisdiction that does not allow it. Better to explicitly allow for each call, like it does currently.
https://en.wikipedia.org/wiki/Telephone_call_recording_laws