Comment by strcat

The reason GrapheneOS doesn't support these additional devices is because they don't provide proper privacy/security patches or security features. Pixels are currently the only devices with proper alternate OS support with a reasonable level of security. That's why we have an OEM partner we're working with towards their future devices meeting our requirements. The hardware requirements are listed at https://grapheneos.org/faq#future-devices. Pixels provide 7 years of proper updates while other devices do not.

Fairphone 4 and Pixel 6 were released in October 2021. Fairphone 4 is on the soon to be end-of-life Android 13 and already end-of-life Linux 4.19 kernel branch. Pixel 6 is on Android 16 QPR1 and the Linux 6.1 kernel branch since it moved to it from Linux 5.10. Fairphone has 1-2 month delays for partial security backports to older releases and years of delays for major OS updates. This does impact another OS supporting the hardware. Fairphone 5 is using the Linux 5.4 kernel that's end-of-life in December 2025 with no plans to migrate to a new kernel. Fairphone devices are missing the security features required by GrapheneOS too including but not limited to MTE (hardware memory tagging) which is the basis for Apple's recent launch of Memory Integrity Enforcement but has been more heavily used by GrapheneOS since October 2023.

GrapheneOS is a much different kind of project than LineageOS and other AOSP-based operating systems. The privacy and security focused comparison table at https://eylenburg.github.io/android_comparison.htm shows that quite clearly.