Routing messages between peers in a decentralized system need to take into account that both senders and receivers could be online and offline at multiple times.
This means the storage location of the messages you are supposed to receive could change often, making retrieving messages a two step process, looking up the current online location and then retrieving messages. The place to lookup messages is fixed in a centralized system, hence you'll receive messages faster.
This can definitely be sped up by increasing the number of times the messages are replicated in the decentralized system and a constant shuffling of the message between nodes to ensure it is always available for the receiver when they come online, hence inefficient.
The fastest way to fan out messages efficiently between a group is through one node that is always online. I think no decentralized architecture can be more efficient compared to a centralized system.
Again, a social network only needs to know whom to send your message to and need not know about the contents of the message, If USPS opened our letters, would we argue for a decentralized architecture where we individuals ourselves drove around delivering letters in our spare time?
How were so many of us tricked into handing over so much control?
This means the storage location of the messages you are supposed to receive could change often, making retrieving messages a two step process, looking up the current online location and then retrieving messages. The place to lookup messages is fixed in a centralized system, hence you'll receive messages faster.
This can definitely be sped up by increasing the number of times the messages are replicated in the decentralized system and a constant shuffling of the message between nodes to ensure it is always available for the receiver when they come online, hence inefficient.