Yeah, I have the same understanding. On Mastodon, an instance is an all on one package. On Bluesky, each component can be deployed separately. The nuance is Bluesky PBC own the Bluesky (iOS, Android, Web) apps, the AppView and the default PDS hosting, I could say it's centralized by default and decentralized at will.
reply> I could say it's centralized by default
replyI'm not sure that's totally right, though, because I (using the entirely default bsky stack) can and do regularly interact with people who are using different PDS and AppView's (like, I can interact with Eurosky and blacksky accounts).
I think the thing that is centralized by default is the bsky moderation layer.