Isn't following hashtags enough? Then you can chose to follow #travel, #tech, #crypto, #beauty or whatever.
Discussion
There is no way to come up with tags for every subject without creating a lot of ambiguity on those tags. Also, content producers can pack their notes with dozens of tags to try to amplify their reach.
That's both true. But Instagram uses hashtag following since ages and it seems to work.
Algorithms on the other hand are client dependent. As Nostre is decentralized and pull-only you will get different feeds on different devices.
Tags are great, but a marketplace of algorithms is essential for Nostr's future