I still main ios and had a pixel 7a with graphene up until about two months ago when the battery started to swell up. Currently waiting for updates about the pixel 10s and more clarification about developer verification being integrated into aosp and how that'll affect gos going forward.
The only thing I felt was missing was a better backup solution similar to icloud, I tried figuring out how to use seedvault but I gave up pretty quickly. As a workaround I just made sure I had a cloud backup solution for different file types didn't want to lose, so I used ente for pics and nordlocker for .txt notes and miscellaneous files. (I know nordlocker catches tons of heat but anecdotally I've never had issues with it and I'm still riding on a very cheap two year plan so it's more economical right now to keep using it until that runs out.)
Aside from that I absolutely loved graphene and it outshines ios in many ways imo. Better granular, fine-tuned control over privacy, security, and app permissions including scopes. Sandboxed google services functioned perfectly and I encountered zero issues with it. Being able to install apps outside the play store is my fav feature and I used accrescent and obtainium for most of my apps.
Best of all the graphene wiki is excellent reading and I learned an incredible amount of info about mobile hardware security, app security, and app development just from being involved with the gos community. Definitely helped me thoroughly improve my opsec elsewhere in my life, not just on my pixel.