I can only wonder how much worse it would be if this was made with HTTP polling.
Server Sent Events is an interesting middle way.
Discussion
I've used that in multiple projects, it's great. If I remember correctly my first Nostr prototype used it, but I think I thought websockets would be simpler and more generic/versatile in the end.
Wait, I know you, you're that guy that writes a ton of interesting things in Clojure.