This is a fundamental flaw in the web. Since we treat a server's name as authoritative, anybody maintaining a replica needs to repeatedly hit that server to know if their remote version is up to date.

If we trusted digital signatures on content instead of server names, we could have a model where a single bit of server load propagates to millions of interested parties. As it is the server must do something distinct for each interested party.

CDNs mitigate this only partially, because mutable data means they have no good cache invalidation strategy.

There's got to be a solution that doesn't involve heaping even more burdensome requirements on those who would dare to publish.