The argument is a case of begging the question: Start with your conclusion, then reason backwards to the justification. It's the case that a federation tends t

The argument is a case of begging the question: Start with your conclusion, then reason backwards to the justification. It's the case that a federation tends to erode. Likewise, it's the case that a centralized system tends to collapse. The question to ask is really one of backing a horse to ride on to be pragmatically useful; winning the technical argument is academic. The fediverse has a few core principles in mind, and they tend to get centered in Mastodon's marketing. So it does make some sense that it gets attacked for being an imperfect realization of those principles, and for being unprincipled in other respects. But in a head-to-head comparison with other implementations of social media it can still claim to be more principled on those things it tried to pursue.