You want me to relay information to you by relaying information to you.

You want me to tell you what I know, so you can then update your knowledge and tell people what you know.

Relays are no different in this sense. They retain information, update it, and share what they know with peers.

The difference is, unlike you, they are dumb. They don’t need to know *what* information you upload, what it means, they don’t care. All they care is that this information is updated / available.