The Ontological Argument - valid or debunked?

[Angrboda]

For example, a warning traffic sign is an objectively better example of a triangle than a spanakopita.

By an objectively better example of a triangle you are claiming that it's outline is a better fit for the definition of a triangle. A triangle has an objective definition of being a figure with three sides. This is not the case for greatness. There is no objective definition of what constitutes greatness, so whether or not a being fully exemplifies the notion of an objectively great being is a nonsense question. It has no sense in which it is true or false.