The thing that protects metadata is onion routing. It's somewhat understandable why that isn't already used for everything. The latency impact is not small and

The thing that protects metadata is onion routing. It's somewhat understandable why that isn't already used for everything. The latency impact is not small and it's unlikely the network could take the load if everyone actually started using it for everything. But it's unfortunate it isn't being used more widely for messaging, where neither of those things are major problems.