That's because we can't replace web servers with Nostr yet. I think Nostr could be way bigger than how we use it now. Like a low level protocol for serving entire websites. Maybe a relay would be the web server, for example. We definitely aren't there yet but I can't imagine social media is the only use case for this. I imagine a future where npubs can be resolved without a specific social media style client. Maybe even in a web browser.