There are some very smart research kernels based around only allowing managed, safe code to be ran, so that language security does all the heavy lifting instead

There are some very smart research kernels based around only allowing managed, safe code to be ran, so that language security does all the heavy lifting instead of hardware security. The problem then, though, is that every language unsafety bug is now a kernel bug that lets you read other processes' private keys or write to kernel memory. Rust is supposed to be safer. There are still plenty of type system unsoundness issues or LLVM unsafety issues that leak through every so often.