Decentralisation on Mastodon is an illusion. For me a truly decentralised thing is where I am a node that transmits and can receive transmissions, like radios. When there has to be a server that's being administrated by somebody, this already puts me in a position where I depend on the people who own the server. This means that if for any reason these people don't like me, they can simply ban me and that's it. Basically the same caveat as with the corp social medias, but on a smaller scale. Mastodon is definitely an alternative to big corps, but it has the same flaws. I don't see it as a way the decentralised community should go.