Progress can be followed here …
https://bugtracker.fairphone.com/project/fp2-android9/
Users who want to test the beta version can do so …
With LineageOS for instance, you can install the genuine Google Apps and services via Open GApps, and then there’s Google’s device registration for the use of Google Apps and services on non-certified Android OSes (to not endanger a Google account with violating TOS) … https://www.google.com/android/uncertified/.
Third party Apps might still not like to run on a Custom ROM, though, but that’s a different matter. Banking Apps with their multitude of security checks are a typical and notorious problem, but in the end those security checks are there for reasons.
LineageOS 17.1 on the Fairphone 2 is officially (in their terms) Android 10 currently, Android 11 seems to be coming up fairly soon as LineageOS 18.1.
https://wiki.lineageos.org/devices/FP2/
https://forum.fairphone.com/t/lineage-18-1-unofficial-test-build/69938