The identity layer of nostr makes all the difference. Many wallets don't support address books so you would be entering the recipient every time.
Hmm, some don’t. But botg WoS and Blink do. Don’t get me wrong. I love Nostr, I am just not sure this is a particularly unique use case.
Other apps might use your phone book entries but nostr is cryptographically secure. I bet that nostr will gain most of its growth from this social graph being leveraged by all kinds of apps.