You may have heard about "the gossip model" which has this horribly confusing name because of the client called Gossip at https://github.com/mikedilger/gossip -- which has nothing to do with actual gossiping. It should be called the "outbox model", that would be a better name.

But take a look at NIP-65. The basic idea is that you can find the relays someone announces they're publishing to and you can read their notes -- and their notes only -- from there. See also the Nostrovia podcast episode with Mike Dilger, https://mikedilger.com/gossip-relay-model.mp4 and https://fiatjaf.com/3f106d31.html