I think the filioque is just a distractor from what the disagreement is really about, that is, the papacy.
I disagree.
Simply because the objections to the filioque predate objections to the papacy.
In fact, it was the introduction of the filioque
in Rome, in the church of the city of Rome, which caused the eastern churches to strike the Popes from the diptychs. This happened in 1014AD.
The fact is, the early church had a synodal form of government in the east and the west. The western church did not just one day adopt the filioque, it was inserted into the creed of the Gothic church (in Spain - this was later to be known to us as the Mozarabic church) in 587AD and no where else!
What makes this significant was that the Spanish-Gothic church was putting this modified Creed into the Mass, inspired in part by the knowledge that the ‘Greeks’ recited the creed in their Mass. None of the western churches seem to have done this before, it was not done under the direction of the Pope and they did not seek his approval.
It took another two hundred years for the Franks to put the creed into their Mass, and they used the Spanish version of the creed. Again, the Pope of Rome was not consulted (although it is said that he disapproved).
But this was beginning to stir up objections in the eastern churches. The Pope could do nothing about it, because he did not control the Spanish and Frankish churches. The Papacy did not have that kind of authority outside of Italy, which is the historical and normal synod for Rome. In fact the Pope was somewhat beholding to the political power of the day …
In 1014AD, the emperor of the Romans came to Rome to be crowned, and he asked why the city did not recite the creed in the Mass. The emperor had them do his coronation Mass with the filioque-creed, and the creed remained after the king had gone. This was when the east removed the bishop of Rome from the diptychs, for he was held to be the Metropolitan of that synod. The filioque had been insinuating itself into parts of the western church over the course of 427 years by this point, and had been a hot button issue between east and west for 200.
Forty years later Cardinals Humbert and Frederic excommunicated the patriarch of Constantinople in 1054, severing the two churches. One of the complaints suggested the Greek refusal of the filioque as one of the reasons.
The modern papacy did not exist yet, it was still being born out of the Gregorian reformation.