What you meant to say was:
Gregory I (AD 540-604), Bishop of Rome, on the title "universal bishop" in a letter to the Patriarch of Constantinople.
That IS the Pope that’s writing cautioning against what it would mean to have a “universal bishop” i.e. One bishop and no others!
That btw is not what the Pope is. He is one bishop, co-equal to the others, with a charism of unity, a Petrine ministry to settle disputes (as in Acts), preserve the faith, and be the final court of appeal. Every other bishop holds real authority in his own right, not as a delegate of Rome.
The Patriarch of Constantinople still holds the title Gregory condemned, though in fairness, the Orthodox would say ‘ecumenical’ means first among equals, not universal jurisdiction. But in practice, Constantinople recently did exactly what Gregory warned against: unilaterally overriding the canonical territory of another church in Ukraine, fracturing Orthodox communion with no mechanism to resolve it.
Which is precisely why the Petrine office exists. (I understand Orthodox don’t see it as that way, and it’s not something I ever think about tbh)
You’ve got this woefully wrong. That caption is a misattribution of intent. Gregory wasn’t writing against papal supremacy. He was writing as the Pope, to the Patriarch of Constantinople, telling him to drop a title. That’s not a critique of the papacy. That’s the papacy in action.
