Here's one reader's attempt: the hidden factor seems to be "the ability of the collective consciousness to achieve a sufficient degree of internal coherence that it understands how the system works and can exercise agency to break the power of feudal lords". Reality changes -> comprehension has to catch up. New mediums of communication help a lot.

The resulting "agency" has historically been pretty violent, when the injustice and tension are too severe. So it's wise to constantly be course-correcting by recognizing the new skins of feudalism and wresting power away from its lords.