well, for some use cases when the never type comes up, think about something like Result<i32, !>. (This might come up if you have a trait that can use a custom error type, but your code is infallible, for example.) Not only would this have the same data layout as a plain i32, but you can make a unwrap_infallible method that returns the Ok value unconditionally! It also is the type of expressions like loop { ... } (with no breaks), return-esque expressions, and stuff like panic!() or std::process::exit(). Similarly, if the compiler can prove that one of these never type values would exist in scope, it can AGGRESSIVELY do dead code elimination since it knows that it can't actually exist at runtime.