All other languages are either not compiled languages with static typechecking or have too few eligible users. C# would also be an option if it wasn't Windows-only.
By looking at the interface an object implemnts, and looking up the documentation of the interface, you then know what you can do with this object.
Yes, it's a good idea to separate the interface from implementation, and only expose a limited set of procedures that can be called. But you don't need manifest typing for that.
A class definition is one way to both minimally document the interface of a module and give its use some restrictions. But if the interface returns an int, and only the documentation specifies which integer values are allowed, then static typing doesn't save you from returning nonsensical values.