First, while the prophecy is supposed to have been written down by Saint Malachy in the 12th century, it was never spoken of even once before it surprisingly appeared out of nowhere at the very end of the 16th century. For a prophecy that supposedly predicts the Apocalypse in great detail, that’s an amazing fact! Would a true prophecy really go more than 400 years without being mentioned even a single time? I don’t think so.
Second, while the prophecy proves to be rather accurate about all the popes before the 16th century, it is extremely vague and inaccurate for the popes who came after.