Yup, I say it when it comes up, corporate, centralized tools inevitably die, they have quarterly goals and on boarding metrics and all that they have to give to investors. Something like Nostr (or bitcoin or anything open source and decentralized really) can continue on indefinitely with 2 users. They'll stick around as long as someone spmewhere needs them, and if not that many people do, fine, but if the time comes when many do, they're there. They only die when they become useless, success metrics have very little bearing.
Discussion
Bitorrent protocol isn't used much by the masses, but it has been around a very long time now, (in computer years) and contuniues to be used more and more. An amazing protocol that hasn't died and will likely live longer than facebook or twitter because it does things no other protocol does. Nostr I think will be the same. Growth is not a metric of its usefulness, not many people use soldering irons but without them the world would be very differnt..