How different would Bitcoin and Lightning be if we had Nostr's social layer before them?
Wallets would mostly send to npubs on the UI, with search by npub or nip05 not addresses. Relays would probably be LN nodes also and could have custody of your sats, so your stats would be spread in many relays, like your notes. They could also offer other services like onchain tx batching maybe or coinjoins.
Very different. The conversation and direction of Bitcoin was and is censored on Bitcoin talk, r/bitcoin and Bitcoin Twitter.