OOP is not needed in most small projects as it only complicates understanding of the code and, as a result, increases time spent on its' reading and monies spent on its' support.
OOP makes life easier when dealing with something really obstructive. Instead of making clusterfuck of dynamically loaded modules and thousands functions in the global namespace, you simplify (or trying to) program structural organization, dividing it into classes and objects. Saves lots of time when amount of actual developers is more than 3.
Oh, and, of course:

object->doSomething(whatever);
doSomething(object, whatever);