That's true and I liked the idea of it until I started writing some Zig where I needed to work with strings. Very painful. I'm sure you typically get a bit faster string manipulation code than what you'd get with Rust but I don't think it's worth the cost (Rust is pretty fast already).

Can't agree more. I hope someone puts some work into a less painful way to manage strings in std. I would but I don't manipulate strings quite enough to support usecases more than basically concatenation...