Decentralized in theory, but not in practice is just centralized.

Also:

So how challenging is it to run those? In July 2024, running a Relay on ATProto already required 1 terabyte of storage. But more alarmingly, just a four months later in November 2024, running a relay now requires approximately 5 terabytes of storage

https://dustycloud.org/blog/how-decentralized-is-bluesky/