@Ric9K Even if it not the right place, I am using stock FairPhone OS (at least for warranty, it sounds me risky to unlock boot loader) without Google account (never accepted conditions) and do not use Google applications/services... even if Youtube still delivers notifications, and Play Store still delivers updates. I have setup F-Droid and use alternatives applications. Next steps are rooting, allow signature spoofing if possible, to replace google services by microG... But probably I will install /e/OS when available for FP4.
I really lack a proper "complete" and "offline" backup/restore process for Android without use of cloud services - typically something like Samsung Smart Switch.