I think people expect Nostr to be the next (every)thing, but to me, after 2 years working at a Nostr startup (@Satlantis: Social Events), trying to use it for virtually everything, I realized Nostr is "just" (forgive me @fiatjaf for the use of "just") the next big thing for identity management.
There's people obsessed with building EVERYTHING on Nostr (I even saw a guy building an Operating System with Nostr). Who knows, maybe one day Nostr will be the everything tool, but at the moment it's a unique tool, a GREAT one to manage our identities in a sovereign way.
Anything else should be built reusing technologies that have longer track records and are more efficient.
Here's an article @Alekandar Svetski wrote about it. He called it "As Nostr As Possible": 

Satlantis Blog
As Nostr As Possible (ANAP)
A more sensible way to build "with" Nostr