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 large instances have a bigger voice proportional to their larger size, but I don’t think that’s really an issue as long as there are plenty of instance options and no single one is so powerful it can force the system to conform to it rather than conforming itself to the system.