Fairphone is a mess software-wise though, both stock or with /e/OS. Ancient kernels, old firmware bundles with many known CVEs, way behind on regular AOSP updates (which are needed for fixes for vulnerabilities not marked high or critical). They only do the minimal ASB patching most of the time. Hardware security is similarly bad, e.g. the Fairphone 6 does not have a secure enclave but relies on TrustZone which runs on the same CPU as the main OS.

Also, it seems relevant to mention that the software is mostly maintained by a Chinese company (T2Mobile), which might be relevant depending on your threat assessments.

For security/software updates it's pretty much:

GrapheneOS > iOS > Pixel OS >> Samsung flagships >> pretty much everyone else.