This is a manipulatively framed question. Mastodon, today, claims to be decentralized. It explicitly says “decentralized social media platform.” In actuality, Mastodon is extremely centralized (domain names are a point of centralization, even if they didn’t intend to censor or manipulative the network social graph, the registrars and registries can do it for them) but furthermore Mastodon has explicitly used its points of centralization to harm free expression. They enforced defederation as a policy to destroy the network graph.

Mastodon and ActivityPub are chronic liars. They claim decentralization fraudulently while never having offered such. They specifically abuse the authority that they have garnered by controlling a centralized network to harm speech and human rights.