Cross platform. You could build a rust app with a WebGPU target that runs across web and native.
Plus, using system libraries (DirectX, Villain, Metal, OpenGL) from Go would be a pain and possibly suffer worse from the FFI penalties than just using a higher level library written in Rust/C++ to begin with.
Google has an implementation of WebGPU called Dawn, which is quite impressive. It's written in C++.