cody on Nostr: I'm not sure which clients are doing this as well, since it's not a mandatory ...

I'm not sure which clients are doing this as well, since it's not a mandatory requirement. This approach is definitely not as efficient as fetching directly from a few relays, but I think it's necessary for a decentralized network. I strongly encourage everyone to self-host relays, and I've even developed a relay that can be easily run by non-developers: https://github.com/CodyTseng/nostr-relay-tray