The problem is that with LLVM, GCC, CUDA, Vulkan, POSIX, V8 and co, there will be lots of new C and C++ getting written as well.

Even on OpenJDK and CLR side, as new language features allow to rewrite even more runtime code from C++ into Java and C#, there is still new runtime code getting written in C++.

There is already clever tech for hardware memory tagging (SPARC ADI, and ARM MTE), CHERI is yet another way to tame unsafety on our computing stacks.