The question then becomes, is it worth it if it's largely unsafe? That's a complex question. Unsafe Rust still does give you a lot of advantages, namely that the checked constructs are still safe, even in an unsafe block. Unsafe Rust is slightly more annoying to write than safe Rust, and so that's a downside.
It's also possible, and again, this is more in theory since I know nothing about wayland internals, that the safe abstraction was chosen to be a bit too low-level. That is, rather than trying to make the primitive operations safer, designing an external API you'd want users to use, rather than one defined in terms of some of the primitives, may make sense. This has a lot of pros and cons, as you'd imagine. And that's also more work to do.