[zzzcpan]

Well, in the context of privacy decentralization doesn't have a lot of meanings. Just a couple, like leaking as little information as possible to a single party and giving as little control as possible to a single party, because if you can't trust a single party having to trust many independent parties with much less information and control is much better for privacy (theoretically not a single party should be able to decode a single bit of useful information about others, even a resoursful malicious party doing sybil attacks, etc.).