Because it's still cheaper and safer to implement in Rust and allow a compiler to mechanically and deterministically transform it into machine code. The value of abstractions are not going away.
There used to be a Pascal to C compiler. CHICKEN is a compiler for Scheme that generated C files. TypeScript is compiled to JavaScript (because we didn't have WebAssembly back then). Other projects use the LLVM compiler infrastructure. If you're referring to this, then fine, but it's just intermediate stuff. The end result is still assembly / binary.