Happy yo answer your questions. 

But the simplest and closest analogy is DNS and WebDav.

Pkarr is a censorship resistant DNS.
Our Homeservers are a nicer WebDav, in many ways, none of which are revolutionary or unfamiliar to web developers.

Some aspects might feel disgusting to Nostr devs, like the fact that data is not signed at client side (not at the protocol level) but we think that is a good thing as it allows for better key management and usage of tried and tested alternatives like good old sessions with cookies.

you can however ignore the homeserver and just put your npub in Pkarr. we just believe that homeservers allows decades of web development to be put to better use.

As you can tell, Pubky core doesn't answer the discovery question, unlike Nostr which starts from discovery then tries to bend relays to be hosting providers with Outbox model.

For discovery we think crawlers and indexers are the normal solution, just like they were for the early web.

But there are plenty of apps that can be built without discovery, and our strategy is to spend the least amount of complexity to achieve the most leverage, before moving to more complex and frankly harder problems in principle (like censorship resistant global search).