If the Eastern Church can't keep itself from falling apart like it claims it can, then no matter which side of Calcedon was correct is immaterial. ISTM the very fact of such schism is the "wretchedness and/or demise of Eastern Christianity".
Truth, if there is such a thing, would still be such even if it was abandoned by everyone. Major schisms have been present from the earliest period of Christianity (2 Tim 1:15 etc.). I think Paul, and even Christ Himself might have understood your feelings, and perhaps your doubts too, but I doubt they would have agreed with your conclusion.
Your points notwithstanding I would still maintain the ecclesiology of the Eastern Church has worked just fine regardless of all the schisms, heresies, heterodoxies, unbeliefs, and martyrdoms added together if in her "we have found the true faith" (as we confess). If on the other hand the gates of hell have prevailed against our Church because there have been schisms, or if we are in a false Church, our faith in her is in vain. I can respect and empathize with your honest doubts; still, I find no reason personally to confess the wretchedness and/or demise of Eastern Christianity so easily as all that.
Slow down, there, pardner!
I am not confessing the "wretchedness and/or demise of Eastern Christianity". I'm just saying that, in the light of history, facile claims that Eastern ecclesiology "has worked just fine" simply don't hold water. In each schism there was plenty of blame on both sides, and we should humbly acknowledge our own failings that contributed to the fragmenting of Christianity.
And I certainly agree that with you that truth exists. The problem is, how do we identify the truth in a given situation? How do we know that Chalcedon was right and that those who rejected it were wrong? When two groups are diametrically opposed, only one (at most) can have the truth, but each most certainly thinks that their side is right. In the absence of a new revelation from God, the Church has to find ways to work these things out. Rome has offered papal supremacy as the solution, but that raises a whole other set of problems. Orthodoxy promotes consensus and conciliarity, and they often have worked successfully. There have been times, however, when it apparently was not possible to achieve consensus, and the sad result was lasting schism.
Not that I'm saying Protestantism or the RC are any better-this is the issue with the greatest chance of making me an agnostic, honestly.
Falling apart? I take it as a demonstration that the Orthodox haven't: the OO and EO, with over a millenium and a half of seperation have been remained close, contiuing to refer to each other, as St. John of Damascus said over a nearly a millenium and a half ago, differing "on....the Council of Chalcedon, being Orthodox in every other way." This is shown by the fact that the Copts, who rarely if ever practice economia, will commune EO and will accept them without rebaptism, chrismation or reordination/reconsecration, and even EO Churches who rarely practice economia have accepted the OO by chrismation or even just confession, as those most vocal against the OO here have admitted. This, despite the near total separation by language, culture, history, governance, etc. over the near two millenium.
In contrast, the West has been divided at the very
most 844 years (preaching of Peter Waldo), perhaps 6 centuries (John Wycliffe and Jan Hus) but most definitively less than half a millenium (Luther and the Reformers), within one general culture (Western European), using one lingua franca (Latin remained a language required at seminary for both my old protestant pastors and my present priest, a graduate of Southern Baptist), and not only has its schisms gone off in all directions, but they are nowhere getting closer to each other. Except for the power of Kumbaya to ignore all differences to bring about a "communion of love."
The EO and OO are the Control group and the Experimental group of Orthodoxy (there being some disagreement on which is which) in the experimentum crucis proving Orthodoxy.