It’s not about the code, it’s about control of the servers and feeds. Decentralization doesn’t just mean multiple servers. It means no single entity has special authority over the user community. That isn’t the case with bluesky from what I can tell.
Old joke: Conspiracy theorist Ted Tinfoil dies and goes to heaven and gets to meet God. God welcomes Ted to the afterlife and asks if he has any questions. Ted wants to know who killed JFK. God says “it was Lee Harvey Oswald, acting alone”. Ted says “oh no, the cover-up goes all the way to the top!”.