I'd say that you are both right. Nostr can assume that there will be n number of entry points, and that some data is more in-demand than others, and which data that is will depend upon the relay's users.

So, databases will have to become smarter about where they store which data and have archiving schemas. People don't mind if something rarely called up is returned more slowly; they're more happy that it is returned at all. But if something popular isn't returned quickly, they will begin to whine about the latency.

I've added return-time display, to our client's search, by the way. Some relays will be setup to return an item fastest, whereas others will be setup to return them most reliably, even when the Internet is generally slower.