> I'm not convinced that replacing one proprietary OS with another is the solution.

Someone correct me if I'm wrong, as I'm not super familiar with Jolla's/Sailfish's architecture, but isn't most of the OS actually FOSS, while there is a thin proprietary compatibility layer, and that's about it? Was some months ago I last read about it so could be misremembering, but seems like a good first step at the very least.