OOP goes much further then just calling functions.
Classes collect functions that operate on the same set of data or share the same goal. But another advantages of classes taking DRY to the next level. With functions, you can encapsulate some simple task so you don't have to repeat that over and over. With OOP, you can encapsulate more complex tasks so you won't have to repeat that.
If you tend to pass the same sort of data to several functions sequentially, you can think about using a class, and pass that data to the constructor and saving it in the class. That way, you can call the functions without having to pass that data each time.
