These are my opinions. I'm mlost likely over-simplifying things.
My mother became an attorney late in life. She had some interesting comments. One was people will fight over everything, anything, ESPECIALLY divorcing couples and families.
Her great aunt and her divorcing husband FOUGHT over who got custody of the bird.
Also, some people HAVE to be right, no matter what.
Sometimes, in religion, particularly, fighting is more an emotional reaction than anything else. Why I would get my shorts bunched up (a guy’s phrase, but SO appropriate) for something like how “filoque” got added to the creed is beyond me. Who cares? Especially after SO long a time since Jesus graced our earth with His presence.
Sometimes I think it’s 99% ego more than anything else.
The Orthodox decision to split based upon how to express belief in a sacred mystery, the Trinity, was very unfortunate. The punishment for that was St. Thomas Aquinas. The decision to split based upon where the center of civilization had shifted was motivated by pride. The Office of the Bishop of Rome is just an office, however with that office comes authority and infallibility, per Jesus’ command. It would be better if the Church breathed with both lungs. As we watch the resurgence of Christianity in Russia we wonder if this was what was meant by the Conversion of Russia and the beginning of the triumph of the Immaculate Heart?