that only works if the method knows about all the types that might exist. The reason overloading is necessary is that the person that writes + for your programm

that only works if the method knows about all the types that might exist. The reason overloading is necessary is that the person that writes + for your programming language doesn't know all the types that people will want to call + on. As such, you need a way to define new implementations of + when people add new types in the future. This forces you to have some form of overloading.