1) Lack of a garbage collector does not make your program faster, it makes the performance more easily predictable in terms of latency.
It also makes it more friendly for memory bandwidth, CPU cache and to overall memory usage, which in turn results in better performance in real-case scenarios vs synthetic/toy benchmarks. This is particularly noticeable in constrained environments (like embedded systems).
2) Zig was never about memory safety, and it is not a memory-safe language.
It might have better plumbing than C, it might add better way to implement and abstract concepts.. but so does C++, for instance.
The more striking differences between C++ and Zig, IMHO, are syntax and the ability to use the same language instead of a separate one to do meta-programming (templates vs comptime).
3) Aliasing enforcement in Rust is there for a reason.
Two examples I quickly found on Zig's issue tracker: