[rumanator]

> The browser has no real concept of "page navigation" or "site navigation" with any kind of state, or the "current" navigation item, or of hierarchy, breadcrumbs, menus, or other core navigational concepts involving site and page structure.

Why do you believe the browser should support that with primitives? Advocating for that kind of specialization lies somewhere between forgetting important and basic historical lessons on software engineering or an unsubstantiated belief that now everything will be different.

> A large part of "knowing about usability" is just knowing how to execute these basic navigation features without goofing up on the many pitfalls available to you.

You're leaving out a part where said usability principles lie somewhere between emerging requirements that are still under development or fads that are scheduled to be replaced with the latest and greatest promising idea.

Suffice to say arguing to force them into browser as primitives is demanding that they should be set in stone as is.