It's very hard to make a proper client that doesn't take shortcuts that undermine the entire point, and JavaScript and browsers are a magnitude slower than what a proper native client should be.
Have you tried Gossip?
Still, it should be possible to do reasonable web clients if you buy into the correct architecture and don't try to vibecode the logic.
I still think Coracle is pretty good. Jumble I like too, but I only use it to browse relays directly -- which is a much easier flow to implement than an outbox-powered "following" feed. Recently I'm playing with https://wip.alphaama.com/ and I like the style, it feels fast enough.
But I must reiterate that all of these still feel slow in comparison with a native client, but they do _not_ feel slow in comparison with almost all other websites on the web, everything is crazy slow, including X and centralized platforms. I've basically given up loading websites on my phone.
I wish all these web developers spent a week with a computer and a cell phone that wasn't the best of the best just so they could contemplate their life mistakes.