I don't think Zig is about expressivity over safety. Many people liken Zig to C, like with Rust to C++.
Zig is a lot safer than C by nature. It does not aim to be as safe as Rust by default. But the language is a lot simpler. It also has excellent cross-compiling, much faster compilation (which will improve drastically as incremental compilation is finished), and a better experience interfacing with/using C code.
So there are situations where one may prefer Zig, but if memory-safe performance is the most important thing, Rust is the better tool since that is what it was designed for.
Zig is a lot safer than C by nature. It does not aim to be as safe as Rust by default. But the language is a lot simpler. It also has excellent cross-compiling, much faster compilation (which will improve drastically as incremental compilation is finished), and a better experience interfacing with/using C code.
So there are situations where one may prefer Zig, but if memory-safe performance is the most important thing, Rust is the better tool since that is what it was designed for.