Less complexity to deal with. No need to worry about external scope or external methods mutating properties on objects. No need to think about constructors or anything else. No need to worry about inherited properties. No need to instantiate the object before executing the method.

All you need to do is define a function and call it.

Literally, again I urge you to take a look at the following example, it's waay more simple than OOP:

https://news.ycombinator.com/item?id=23338700