Fields like event id, sig, pubkey, p & e tags would be 50% smaller in binary vs utf-8 hex. Follow lists are currently quite large and their size would be basically cut in half. But if we implemented NIP-114, we could save even 90% or more in bandwidth and some processing as well, depending on how many relays you connect to. Hoping to find some time for it again. https://github.com/nostr-protocol/nips/pull/1027