Rust is good at many things, but it's not as attractive for Python for the sort of program you write when a shell script gets a bit too complicated and you want to write it in a proper language.

So Rust can get away more easily without having support for things like command line parsing in the standard library, because it isn't really trying to support situations where it would be inconvenient to give your program its own project directory and Cargo.toml and all.