Zig is pretty good for my use case. It may not be fully pollyglot at a technical level, but I can use it for my embedded C use case, for Jank to export the .cpp to other platforms, and thereby Clojure.
the problem is that you need a compiler capable of compiling said zig, python, rust. LLVM does that, you can compile something as untyped as javascript(with a lot of hacks) or as strict as rust.