If you care about personal privacy, any replacement firmware will be an improvement over what a smartphone vendor provides. The trick, for most people, will be balancing the competing needs of privacy, compatibility, and convenience. Graphene ought to score highly in both privacy and compatibility, but it only supports a few devices, and its security hardening can make it quirky. ∕e∕OS scores for convenience and support if you’re a Murena customer, but has little to recommend it over Lineage otherwise, in my view. Lineage probably remains the geek’s choice, despite the maintainers’ increasing disdain for tinkering with it.
Using any replacement firmware will be inconvenient if you’re tied to Google’s services, as many of us are. You can try to continue to use those services, but in a less privacy-crushing way, and Graphene and ∕e∕OS purport to offer some help with that. However, I think you’d need to be both knowledgeable and careful to use Google Services, even in these restrictive environments, without inadvertently sacrificing privacy. To my mind, if you want to de-Google, you have to find replacements for Google, not ways to appease Google.
As a Graphene user, I can agree about the ~~frustrations~~ quirks of the OS.
I was looking for reasons to switch to Lineage, but I think I am not yet geek enough to make the switch.