Politics of course.
While your on the subject of Primacy. The rankings of cities are purely civil and this ranking is never to be confused with primacy or jurisdiction with the Chair of Peter, as some posters in the past mistakenly confused; the difference between the rankings of Church’s on civil matters such as you perfectly indicated “Political”, with ecclesial matters exercised by divine authority such as the council’s proclaim the Bishop of Rome possesses.
Let it be noted here, that the civil primacy of rankings of Church’s which the Patriarch of Constantinople introduced a new and secular ranking to recognize the Patriarch of Constantinople as second to the Bishop of Rome and is never equal or second to the Bishop of Rome on Eccliesial matters or by divine authority, which Jesus gives, not the Emperor’s or the Patriarch’s of Constantinople.
When the same council ruled after it’s proceedings and readings concluded in the official records that the Bishop of Rome is to be recognized as Supreme over all other Church’s given to her by divine authority over all Church’s by Jesus Christ.
After the Patriarch of Constantinople usurped her ranking over Antioch, Alexandria, Jerusalem, when She never existed prior to the latter (Apostolic see’s) listing disproves any Pentarchy ever existed and from these Constantinople civil politics begin our way into many different schisms.
I think it’s funny also how most Orthodox posters give too much credit to the Pope as a superhuman, or supreme being having superhuman powers.