OSX is a certified UNIX.A bunch of BSD people ended up over there. Android and ChromeOS use the Linux kernel and Redhats C lib. The one time I checked it looked like most of there compositor and components are also C/C++, skia etc. Windows is written in C++ and you have WinAPI. And of course vanilla Linux is C and all the GNU libs are C.
So its WinAPI and Linux system interface with a preference for POSIX. With lots of other irreplaceable Libraries that are also only written in C/C++. High performance high memory usage that needs to run stable at full load and maximum memory for days at a time.
Keep in mind that there are large industries that have usage and development patters that your oblivious to. And that claims of safety espoused by language developers based on criteria that they themselves have created are so low on the priority stack that there simply non existent in specifications.
What should we do? Should Google and Microsoft and The Linux foundation rewrite there whole stack in XYZ meme language? Or is it just all the other companies that that should switch to a language they don't need or care about just for the hell of it?