An example: lots of instance admins acted in unison to identify and ban instances and users who spread child pornography last year. They did this for their own reasons, but as a sum total of action it was largely indistinguishable from a centrally managed action.
I've implied elsewhere that nothing stops dishonest actors from starting Masto instances. The cost of failing is insignificant. There is no penalty for being revealed a fraud.
That's progress and we shouldn't cede the point to folks who want to try and claim Mastodon is uniquely bad in this fashion.