I've flip-flopped on this a couple of times since we last spoke and I'm back to agreeing with you. Did you see Fiatjafs implementation here? You can use the whole nostter(.)app for a single relay, as if the whole app is a community-specific-client.
Discussion
Yup, Nostr works like that by default.
Note that Nostter.app is just kind 1's.
On noStrudel you can set your app relays to 1 app relay and dive into Articles, Wikis, Emoji packs, etc... from the ~~relay~~ community
But of course, ideally you built for all of this from the start: