Authoritarian Left - unstable, doesn't scale, dependent on the efficacy of the central planner, prone to despotism. (dictatorship)
Authoritarian Right - bureaucratic hell, systemic inflexibility, adapting to new circumstances requires a chain of approvals from bottom to top, prone to tradition-based decision making. (the military)
Libertarian Left - groupthink, requires constant engagement of all elements, prone to stagnation if there is no majority consensus, prone to mob justice events, prone to suppression of individuality. (the Borg)
Libertarian Right - chaos, unpredictable outcomes for any particular element, prone to local injustice for elements in local groups, prone to "might makes right" in local groups due to lack of broad oversight. (feudalism)
Well... this is more about purity of form... my descriptions above are what happens when each form is taken to its exclusive extreme, so it's not necessarily distopian, it's the consequences of reality.
If you had even one perfectly benevolent person you could have a perfectly benevolent dictatorship, though it would still have scaling problems when the one person can't handle every issue that comes up. If everyone were perfectly benevolent then pure collectivism could work, though there's also a scaling problem if every person must participate in decision-making for every problem all the time.
Rigid adherence to any structure becomes its own sort of totalitarianism. None of these can really be good (or utopian) in itself, the only really good option is to keep the structure itself flexible, but with a strong enough set of guiding principles to prevent local abuses.
Authleft - capable of perfect distribution according to a united plan, information received directly from the source, reduced vulnerability to outside/subordinate influences (Cyberocracy)
Authright - Coordinated planning with flexibility of command, independent units able to pursue goals via mission-oriented approach (The Military, but a competent one)
Libleft - Communal decisionmaking, information is distributed to a wide variety of actors who may have unique insight or suggestions, resistant to takeover of institutions of power (Anarchy)
Libright - High and rapid transfer of information with minimal interference or coordination cost, low ability to capture the decision-making apparatus totally (Market systems)
I believe so, though my understanding of the technicals of ActivityPub is pretty sparse. It's all Greek to me, lol. I think that extreme expansion and extensive defederation would create something more like the emergent behavior, whereas now, everything is still pretty closely interconnected (within a degree or two) and more 'consensus' style.