Marmot is a subprotocol based on Nostr (and MLS signatures): https://github.com/marmot-protocol/marmot that's used for private messaging while using Nostr for identity.
Your specific example is true - nostr currently doesn't have generally available key rotation solutions, there are couple proposals in works thought. This is also noted in the article with "Nostr is not perfect. Key management remains challenging, though solutions like NIP-46 and hardware signing devices are emerging."
Sidenote - the article you just read is hosted on nostr. Did you notice that? The comments under it are powered by nostr, etc. It's pretty seamless - habla.news is just one of the client apps that fetches it from many relays. Nostr phone apps (like Amethyst) also display the same article and allow interacting with it, commenting, etc.
Your specific example is true - nostr currently doesn't have generally available key rotation solutions, there are couple proposals in works thought. This is also noted in the article with "Nostr is not perfect. Key management remains challenging, though solutions like NIP-46 and hardware signing devices are emerging."
Sidenote - the article you just read is hosted on nostr. Did you notice that? The comments under it are powered by nostr, etc. It's pretty seamless - habla.news is just one of the client apps that fetches it from many relays. Nostr phone apps (like Amethyst) also display the same article and allow interacting with it, commenting, etc.