Most people will say reusability, but function's already got that covered. Classes describe objects and this is something that is very useful. Imagine this, you are building a game, and each character has a unique punchline or weapon, a class can accurately describe this object. Sure this could also be achieved using functions, but classes solve this problem in a neater and more expressive manner.
OOP isn't about creating re-usable classes, it's about creating Usable classes.
OOP provides a lot of features that makes it a robust solution. Below are just a few of those features.
number_of_limbs() on an object, which will work whether the object is of class Animal or class Dog.Yes, there are benefits. OOP always has its benefits. Sure there are languages that are more on the functional side, that doesn't mean that they can not have a touch of OOP. OOP done right is a really beautiful thing.