> I think the underlying question is why move to Zig from a C variant?

Null pointers disallowed by default. Slices. Superb cross-compilation. Easy C interop. Comptime instead of C preprocessor.

There are lots more.

The problem Rust is up against is that the number of people who want Rust simply because of "strict typing" far, far, far outnumbers those who care about safety or speed. And that leads to the issue that most people really should be using a GC language like OCaml rather than Rust.

Unfortunately, the OCaml ecosystem ... :(