Personally I'm pretty happy with GrapheneOS (Android AOSP distribution) and also donating to it. It works for me, its licensed under a free software license, there are plenty of cool free software applications available. I'm familiar with Android application development if I need something custom.

Unless Android (itself, not Google Play Services because I don't depend on them) goes closed source I don't see a reason to switch to something (imo) inferior.

I have nothing PmOS, phosh and other free mobile smartphone projects and will probably redirect my resources towards them if Android goes closed source.