Replacable battery is a killer feature since the proprietary "broadband module OS" host and BLE threat is still out of full control for the virtualized Android.
If you only use FLOSS apps and a still maintained fone, LOS without GApps, microG is a good alternative, combined with network filters (NetGuard, AFWall+, AdAway, Pihole...). Mayb also root can be considered which is afIk not easily possible on GOS but gives back freedom to users with special needs.
I personally understand people who dont want to support Google by buying super expensive Google hardware.
Your choice also depends on what threat scenario and against which kind of attacks you like to be safe from.
If you are dependent on proprietary apps, which must be considered compromised on a higher level security environment, GOS is def. the better option.
Though GOS, too, cannot make u immune to attacks from 3 letter agencies.