What is the potential complexity or problem when there is no polymorphism in object-oriented programming?

The absence of polymorphism in object-oriented programming leads to reduced flexibility and extensibility of the code. Without polymorphism, you have to write many conditional statements (if/else or switch) to handle different object types, which complicates maintenance and increases the likelihood of errors.

For example, if you have several classes with similar methods, without polymorphism, you will need to explicitly check the object type and call the corresponding method, instead of simply invoking the base interface method. This violates the Open/Closed Principle and results in code duplication.