Yes, but Nostr takes it a step further with the signed, atomic events. Adds another layer of possibility.
What a local relay does is allow you to work offline and create a local hub. I'm the test case, as I commute on a 2,5 hour train ride through internet black-holes, so I need an app that automatically syncs, when the Internet "turns on" and then switches back to local-only, when we go through a tunnel or something.
Also, just fuck the constant wss streaming. Nostrudel or Amethyst are polling over 100 relays, simultaneously, and Primal connects so horribly, that my browser crashes. GB and GB of text messages, every damn day. Mobile plan is empty within a week, and then I've got 3 weeks of snail-mail Internet connections. Great.