Wandile:
I have seen certain Eastern Catholics literally deny core dogmas of the faith (Papal Supremacy and infallibility, Purgatory, Filioque etc) and yet still claim to be catholic. This is ridiculous. There’s is only one Catholic faith and Catholics believe the same things in the west, east, north and south. Truth is not limited to geography.
While I do agree with your conclusion (Catholicity is not a matter of geography), Western Catholics behoove themselves to learn about the history of all these “dogmas” you have mentioned, and how they were developed and imposed upon the faithful. Geography and politics have had a role in separating members of the One Faith, as well as language.
When dogmas were imposed upon the Latin faithful without the participation and knowledge of the Eastern faithful, it appears that it is the Latin Church that has departed from the One Faith they once all shared.
One of the fundamental values of each lung of the Church is that we are not at liberty to change what was handed down to us - the Sacred Tradition that has been infallibly protected in the Church by the Holy Spirit. Among these expressions of the faith are the Creeds. Adding a phrase to the Creed that appears to change the meaning of what was preserved is an affront to Eastern sensibilities.
And the proclamation of the supremacy and infallibility of the Pope is even difficult for Latin Catholics to bear. Jesus was clear that His kind of leadership was not one of supremacy - to be “lorded over” others, yet this proclamation appears to be the opposite.
There are good reasons why it is prudent to withhold judgment about our Eastern brethren “denying core dogmas of the faith”.