> in the real world we need at least polymorphism and operator overloading

Maybe in your real-world ;)

Building your game code around classes with virtual methods has been a bad idea since at least the early 2000s (but both static and dynamic polymorphism is something that Zig can do just fine when needed), and the only important use case for operator overloading in game-dev is vector/matrix math, where Zig is going down a different road (using builting vector types, which maybe one day will be extended with a builtin matrix type - there is some interest in using Zig for GPU code, and at least this use cases will require proper vector/matrix primitives - but not operator overloading).