[Hnrobert42]

If I understand correctly, the author presents a case for securing DNS by moving away from a shared directory toward application-specific directories. At the end, he takes a sharp turn to worry that such a move will tear apart the openness of the internet. I suppose an analogy is moving from phone numbers, with shared telco-managed directories, to chat apps managing their own directories. You can’t contact me on Instagram with my HN handle because they don’t use shared directories.

Ok, but there are more important reasons. Walled-garden directories is a symptom not a cause. For that matter, SNI and path-based load balancers are examples of the application-level address resolution overlay already in practice. Those techniques merely implement, not drive, balkanization.

Basically, application-layer DNS doesn’t pass the “but for” test. As in, it is not correct to say “but for application-layer DNS, Facebook/WeChat/Google couldn’t build walled gardens. With it they can.”