An interesting article I saw (from 2019) describing the potential intrinsic tendency for decentralized platforms to collapse into de facto centralized ones.
Author identifies two extremes, “information dictatorship” and “information anarchy”, and the flaws of each, as well as a third option “information democracy” to try and capture the best aspects of decentralization while eschewing the worst.
Someone said the link is broken so here it is: https://rosenzweig.io/blog/the-federation-fallacy.html
I agree with him that there is inevitably a strong tendency toward centralization, but I think a key feature to help with that would be the portability of one’s account to new instances. Even if the majority of users are in only a few instances, there is still a safeguard against one entity (I.e. corporation) directing the health of the whole system. If accounts were portable, when an instance went foul, people could move and the system as a whole would self-heal.
Nonetheless, it’s an interesting article. And the cost and challenges of running a web scale service are not conducive to small time players.