For as much as I like https://nostr.band/ I think it will be sad if we end up with a handful of search engines indexing the entirety of the Nostr public network. If Nostr is successful it will be hard for hobby search engines to exist, right? The amount of stuff will be too huge.

Does it make sense or does it scale to have search engines that prune content and only keep references? Or search engines that only index content from the last year from a set of relays? Or only from a set of public keys according to some algorithm? I don't know.