Objective-C is so beautiful in those regards. So many things are abstracted and optimized for you already, especially compared to Android and their libraries. Rapid prototyping is insanely fast if you can handle yourself in Xcode and around Obj-C.
Interface Builder is more than just an interface builder, it is a serialized data builder. That distinction means that you can instantiate virtually any class in your project without having to write a line of code. It is not limited to just UI elements. That turns out to be pretty powerful.
Below that level, the deserializer exploits a number of properties of the Objective-C's dynamic runtime in order to provide that instantiation of random objects and properties. There are certainly other languages that can be exploited in the same way, but it is not something that can be done directly in just any language.
Without Objective-C, or at least something like it, there would be no Interface Builder as we know it today.