DeGoogle Yourself

DeGoogle doesn't make sense if keeping google services and google play (this provides services any ways). For example grapheneOS as best as it is for security is not a DeGoogle experience. calyxOS would have been an option but it's currently out of maintenance. LineageOS with f-droid basic, apkupdater (apkpure mirror) if needing proprietary stuff and maybe aurora store if apkpure doesn't find something or you distrust it (it'll be connecting to google play), and for them, if needing google push notifications (most of them do) and unavoidable services then microG.

Some FLOSS apps requiring push notifications allow to use unified push btw, like jami and davdroid (davx5), molly (signal client, though I no longer use signal), so no need for google push notifications, and for email imap has supported it's own push notifications mechanism for way long (fairemail, thunderbird, etc). It's on proprietary apps which mostly that's not the case... Installing from official f-droid I believe gets rid of proprietary google stuff, including dependencies on google services library...