What chat gpt is saying is a different thing. You always need to join public chats in Nostr. There is currently no standard for following public chat channels. In the sense that even if Amethyst solves this in our way, other clients will not show the groups when you join. Anigma, for instance, also only stores groups locally. Each new login is required to re sign up for each public chat. We can work on a new standard, but this will take some time.