Our client is one of the few I can even use, since my Internet is often really bad. Amethyst is completely melting down, at the moment, because my connection is fading in-and-out.
Nostr does suck. The NDK that much of the nostr protocol is running on is BAD. Very, very non-performant. nostr:npub12262qa4uhw7u8gdwlgmntqtv7aye8vdcmvszkqwgs0zchel6mz7s6cgrkj and nostr:npub1fjqqy4a93z5zsjwsfxqhc2764kvykfdyttvldkkkdera8dr78vhsmmleku are doing ridiculous amounts of work to improve for relays can run.
All Clients that I'm aware of are junk in terms of how data is used. Redownloading stuff, poor caching practices, etc. Are killing performance unless you have really good hardware on a really good network. This needs to change. Fundamentally, data efficiency needs to be addressed, or nostr will never be able to grow as it should.