"Read the rest of this story with a free account." No thanks. But judging by the title, it seems click-baity. The "biggest mistake" is definitely not OOP. You

"Read the rest of this story with a free account." No thanks. But judging by the title, it seems click-baity. The "biggest mistake" is definitely not OOP. You can definitely abuse and misuse OOP, where other abstractions would be a better pick, but it's not just universally bad.