That's the main reason. New OSs like Fucsia have started being written in Rust, and part of OSs, including Windows and now Linux too, have also adopted it. If

That's the main reason. New OSs like Fucsia have started being written in Rust, and part of OSs, including Windows and now Linux too, have also adopted it. If we had more mature systems languages suitable for OS development sooner, people wouldn't use C and C++.