Because Go is kind of a Steampunk design. The creators collectively ignored decades of PL developments. What that nets is kind of a C without sharp edges, but can't be used where C can.

Rust is definitely jarring to look at, in the same way that decoding some strange C declaration can be, in ye olde days when you had to float all this context in your mind while doing work. But with modern tooling who cares: "explain this lifetime to me"