Main reason nostr cannot scale, not enough passionate people to do it for free or at their own cost. It’s technical limitations make this a larger burden. They want to avoid P2P but scalability requires a large amount of autonomous processes. Scaling a non-p2p system requires more humans for more nodes. All human operated hub based peer systems have failed to date. Edonkey, etc… The human central point of failure is vulnerable, lawsuits etc…