Comment by grapheneos

An incomplete port of GrapheneOS to Fairphones will be missing many of the core security features and won't have reasonable security updates. Fairphones are nowhere close to reasonably secure devices.

Most people expect to have decent encryption without a strong passphrase, at least 5 years of security updates and a lot more. Fairphone says they provide updates far longer than they do for many components, and those come with substantial delays. Fairphone 5 and earlier have end-of-life kernels without security support. That's a very bad situation and is widely ignored. The more recent devices are headed to the same situation for the Linux kernel and other components.