OO and Function Pointers

From https://blog.cleancoder.com/uncle-bob/2014/11/24/FPvsOO.html

For all the hi-falutin’ rhetoric about OO and “real-world objects” and “programming closer to the way we think”, what OO really comes down to is that OO languages replace function pointers with convenient polymorphism. … How do you implement polymorphism? You implement it with function pointers. OO languages simply do that implementation for you, and hide the function pointers from you. This is nice because function pointers are very difficult to manage well. Trying to write polymorphic code with function pointers (as in C) depends on complex and inconvenient conventions that everyone must follow in every case. This is usually unrealistic.