The whole point of nostr is being purely public information system ... Because the way Bitcoin shall be used by nation states and corps as a reserve currency , which you obviously want in public ledger .. same way .. nostr is findamentally designed for AI bots .. you want all their communication in public domain ..
As for privacy .. which I agree is useful for humans .. there are many private communication tools ... What revolutionary would you do beyond say WhatsApp , Signal or SimpleX .. and why ?