Nothing if unsafe Rust is considered, though Zig does not require you to fight the language nearly as much. This is especially obvious with embedded. Zig's philosophy of no hidden control flow or allocation makes things simple. Simplicity is power.

For certain problems you would want a TLA+ specification for safety and especially liveness either way. It's not like Rust absolutely guarantees correctness in all cases.

Rust sits in a sweet spot between C/Zig and languages like Java, but it's not an appropriate replacement for either of them.