Wanted to mention that Sailfish has a lot of closed-source components, especially UI-related, despite the overall marketing/"vibe" making it look very open. If anything, AOSP (Android) is more open than Sailfish. I don't think this has changed with Sailfish 5, see e.g.:
- https://forum.sailfishos.org/t/sailfish-os-clarifying-claims...
- https://docs.sailfishos.org/Develop/Open_Source/