Nostr is great for privacy and for crypto, but not yet suitable for the general public.

Asking an average user to secure a cryptographic key for their identity, when most can barely hold onto a user:pass, is kind of ridiculous... so Nostr is selling a $100 "authenticator box". Not particularly user friendly.

One strong point of Nostr is Bitcoin LN integration, which potentially could work as a source of revenue, but the look&feel is not published enough, while at the same time trying to offer more interaction types (like the marketplace), than what people really want: Twitter's sweet teet.