I don't see how that's a negative, all the choices attached to Mastodon hosts are distributed to multiple services in bluesky which optionally could be served by the same entity, but doesn't need to be. A PDS can run its own moderation services, or subscribe to another, or leave it to clients. A PDS can run their own feeds, or leave it to others. Clients can choose to use the services provided by the PDS, or to use others.

I don't see where the centralizing forces are (other than economy of scale stuff). Having the most users doesn't mean much when it's trivial to substitute your service, regardless if that's a moderation labeler service, a collection of feeds, or whatever else. It's really just the most popular client apps which have disproportionate power, but that's true for every protocol.

Edit: I also want to point out that the PDS by default controls a bunch of stuff for the client via the appview service, that's the service which the client talks to and it assembles your home feed and assemble post views (where it control sorting, etc) and it apply blocks and mutes and applies the PDS's own moderation, and it forwards moderation labels on posts (like NSFW tags) to the client.