Jake is absolutely spot-on here. There’s been a lot of excited talk about adding an
h element to HTML but it all seems to miss the question of why the currently-specced outline algorithm hasn’t been implemented.
This is a common mistake in standards discussion — a mistake I’ve made many times before. You cannot compare the current state of things, beholden to reality, with a utopian implementation of some currently non-existent thing.
If you’re proposing something almost identical to something that failed, you better know why your proposal will succeed where the other didn’t.
Jake rightly points out that the first step isn’t to propose a whole new element; it’s to ask “Why haven’t browsers implemented the outline for sectioned headings?”
(I added a small historical note in the comments pointing to the first occurrence of this proposal way back in 1991.)