GrapheneOS OG.
I got the 6A to dip me toe in half expecting to have to run an iPhone as a second device for fussy apps. That wasn't the case at all, daily driver no issues for me even without Google Services installed.
No notifications for my banking app (due to no Google Play) which I can live with.
Switched to all open source apps where possible.
Love it. Fully tempted to get the P7Pro for the bigger screen...