missing-root
hardened malloc
It has it on some devices, but it may be more limited without the 48-bit address space support, etc. Also, no hardware memory tagging.
hardened kernel
Significantly less hardened on most devices.
sandboxed play support
They don't include it.
permission system
They don't include Storage Scopes, Contact Scopes, etc. They include the Sensors and Network toggles but likely not all of the changes to improve them.
auditor app compatibility
No, but we would be willing to support it if they were interested.
The world runs Android and Pixels are a small fraction. So it may not be state of the art, but works. And replacing stock OS on such devices would still work, and be a good alternative.
Most devices either don't permit installing another OS or don't properly support it. They often disable important security features with an alternate OS. Alternate operating systems also often don't properly update the firmware, etc.
If the device lacks the basics like monthly security updates, what's the point?
It should always be expected that people buy a device to use GrapheneOS. Adding a dozen more phones wouldn't change it significantly, and then people would be buying dramatically less secure devices to use GrapheneOS.
resonably private
reasonably secure
Most of the list of requirements at https://grapheneos.org/faq#future-devices is essentially for providing a reasonable level of privacy and security. These are not niche features.
easy to verify integrity OR
easily reflash the OS from a trusted machine and restore backup from seedvault (?)
You don't get the ability to properly reflash to wipe away a compromise without having working verified boot with downgrade protection for the firmware.
Verified boot is not one of the top 5 most important things in that list of requirements. The top 5 most important things on that list in no particular order are the 3 about updates, the 1 about proper alternate OS support and hardware memory tagging. There are other things there that are also more important than verified boot. We consider verified boot with downgrade protection for firmware and the OS to be a hard requirement, but that doesn't mean it's even near the top of the list of the most important requirements. It's a common misconception that lack of verified boot for an alternate OS or broken verified boot is why we don't support other devices, but that's wrong. It's just one of the things that's often missing elsewhere. Proper privacy/security patches is right near the top of the list and is one of the most frequently missing requirements.