Ahh, thanks for the correction, it's the window manager that's closed (lipstick-jolla-home). Regardless, I will stand by my statement that a fully open-source build of AOSP is significantly more complete and useful than a fully open-source build of Jolla.

If we're going to start counting forks, we get to count LineageOS and GrapheneOS for Android, and then the goalposts really move.

A pure AOSP distribution is now lacking a lot of basic apps. Distributions like LineageOS or GrapheneOS fill the gap with their own, but pure AOSP is totally unusable.