Since you mentioned Fairphone, another option as custom ROM would be e/OS which is not only supported but also comes pre-installed on fairphones (if you choose so). Sure, there are differences to Graphene, but I installed e/OS on my fp6 a few weeks ago and Im super happy with it - no more Google! And battery performance is pretty decent, too.
Tbf, never been an Apple guy, so I cant say how the switch would be for you, but coming from Xiaomi-Android it felt really refreshing :D
Since you mentioned Fairphone, another option as custom ROM would be e/OS which is not only supported but also comes pre-installed on fairphones (if you choose so). Sure, there are differences to Graphene, but I installed e/OS on my fp6 a few weeks ago and Im super happy with it - no more Google! And battery performance is pretty decent, too.
Tbf, never been an Apple guy, so I cant say how the switch would be for you, but coming from Xiaomi-Android it felt really refreshing :D