> You don't need to use any polymorphism (generics or traits) in Rust. You can use it as a pure structs and functions language like C
This just means that the Rust language does not have the feature of being simple. Of course, there are sane subsets of C++ also (e.g., do not use new/delete), but this does not mean that C++ is a sane language. The same goes for Rust, probably.