Is there a way to support varying the meaning of "+" etc without introducing a lot of complexity? I suppose if Zig had nested functions, and the ability to define a nested function called "+", then you could have name shadowing instead of "overloading".

OCaml basically gives you operator overloading this way without actually doing overloading. I'm wondering why we can't have these OCaml-isms in other languages - without needing to use OCaml - which sadly comes with other commitments.