Addressable URLS are the essential building blocks of the web. Completely obscuring them in browsers is a tremendously bad idea.
Technically, obfuscating the URL seems to solve the security issue. But technically, decapitation seems to solve a headache.
I agree with Jeremy. The proposed design feels like it tries to solve the problem by way of gross oversimplification. As a first pass to provoke a design discussion, that’s fine. But it needs to be followed by more thoughtful and nuanced proposals that don’t detonate the core usefulness of a critical piece of browser UI.