Assuming you are serious:
Bluesky is ... arguably 'federated', but it is centralized, not decentralized.
https://gigazine.net/gsc_news/en/20241128-bluesky-decentralization
Their model (AT Protocol) relies on a central, authoritative ... 'Relay', that all 'federated' users and posts on federated PDS (personal data servers) must go through, to actually reach the 'AppView', ie, what all other people/users can actually see.
So, this is not a many to many, tangled spider web of connections, the way lemmy, and other parts of the actual fediverse are.
It is a top down hierarchy, a pyramid.
And Bluesky runs the Relay, the chokepoint.
If Bluesky cuts off the PDS your account is on, everyone on it is now gone.
The actual fediverse, Mastadon, Lemmy, etc, runs on ActivityPub.
In that model... every instance is essentially self contained, and every instance that is federated communicates with every other instance that is federated.
Each instance can decide what other instances they want to federate with... and users on each instance can personally block even more other users, communities, or entire instances if they choose to, but that only effects what that particular user sees.
That is what you call decentralized, approaching, or also having elements of being 'distributed'.
To bring up an example without getting into the drama that led to it:
The 'Tankie Triad' of ml, lemmygrad and hexbear have had a number of other instances defederate from them.
But, there are also a good number of instances that have not done so.
So that means if your account is on hexbear... you can't see or post on an instamce that has blocked your instance.
But, if you (a hexbear...ian?), post on a neutral instance... users on that neutral instance will see the post.
But but, if a user from an instance that has defederated from hexbear goes to to the neutral instance... they will not see the hexbearian's post.
This sounds complicated, and it is, but ... thats the whole point of a decentralized system. It is more complex in the abstract... but the entire system ends up being more robust, more adaptable, more customizable... without a central authority in direct control of the entire system.