> You post to your outbox relays and find content from your inbox relays.

Not really. You post to your outbox relays + you post to all of the other read/inbox relays of anyone tagged in the event.

To find content, you have to use a mix between inbox and outbox. Your notifications come from your inbox. Your feed comes from every follow's outbox. The replies, zaps, and likes to each post come from the follow's inbox.