To quote you: “they don’t want to rewrite everything” …
Writing Rust often implies major refactoring and it takes so much time to write that your requests go: “pewf” closed due to the amount of effort it takes.
Anyway, been there, done that! Zig is probably the real future; it’s a joy to write, it compiles fast, clear to read, and safe.
It has shared libraries and a proper integration with existing C/CPP code base.
You should try it, that’s an amazing language with a real potential to replace the legacy.