> it's definitely not just a C++ oddity, it's a pretty fundamental aspect of Java, JS, PHP, Python, ... Yes, but I'd argue that's because all those languages j

> it's definitely not just a C++ oddity, it's a pretty fundamental aspect of Java, JS, PHP, Python, ... Yes, but I'd argue that's because all those languages just blindly copied what the massively successful C++ was doing at the time. Nobody gave it a second thought. From the perspective of language capability, polymorphic inheritance doesn't give you anything that you cannot achieve with polymorphism and inheritance alone. In fact, there was no polymorphism outside of virtual methods in C++. If you want polymorphism, you have to implement it through virtual methods, there's just no other way.