The epode is of a different meter than the strophe and antistrophe. For example: iambic tetrameter, iambic tetrameter, trochaic dimeter. This change of meter is a great way to make a final point without being over the top in terms of diction.
Pindar, as a poet, was determined to preserve and interpret great deeds (athletic and heroic) as divine values. He did this by writing odes to celebrate such victories or values. We write odes for these reasons, even now.