I found an admittedly old comment from Sam Noble that I thought was worth sharing, because it is thought-stimulating.
If we look at the ‘pentarchy’, say, immediately before Islam, we can find a variety of different self-contained ecclesiologies: Jerusalem exists basically as a very small, tightly-knit local Church, closely tied to the imperial court due to pilgrimage and the internationalized monasteries from which it drew its bishops. Antioch was very far-flung and decentralized, both with individual bishops within the Patriarchate having a great deal of authority and far-flung ‘catholicosates’ existing with practical autonomy. Constantinople, of course, was basically subservient to the court, and when it wasn’t, exile of a bishop quickly resolved the situation. Rome followed a model of ever-increasing centralization somewhat more moderate than Alexandria (the importance of sees such as Milan and Aquileia in balancing out Rome early on is under-emphasized today and deserves reexamination) with obvious political rivalry with Constantinople.
Which is all to say, a genuine return to first millennium ecclesiology would amount to enshrining the modern Orthodox ecclesiological free-for-all, with disputes settled through ad-hoc negotiations or councils calling outside bishops from wherever seems convenient, following temporary mini-schisms. The first millennium looks very much like what is going on now between Romania and Jerusalem or what went on to resolve the messiness in Jerusalem of a few years back…
And I think such a ridiculous, messy non-system is a good thing. Very often Roman arguments for the papacy (and for much else besides!) rest on nothing more than a kind of emotional need to feel like there’s a system behind it all when really there’s not, never has been, and wouldn’t be even if we pretended there was one.
The Church, like an extended family, is a community tied together by mutual love. Of course it’s going to be messy.