[Skeime]

Trying to shoehorn this onto the existing headings was a mistake. They should have introduced a new <h> or maybe <ha> (heading-automatic) element for this. Plus, support in the form of a CSS pseudoclass like :heading(n), which matches <hn> headings and <h> elements nested in n articles/sections/..., would have been great.

Essentially, it was hopeless to expect that designers would adapt their stylesheets to style headings based on the number of sections surrounding them. And if the visual styles don't adapt, nobody will use the outline algorithm to choose their headings.

(Which is sad, because the algorithm makes content nicely nestable. With the algorithm, I can take an article that was independent and use it as a section in a larger work, and the headings will automatically adapt. Though, as a pet-peeve of mine, nested IDs would also be somewhat necessary for this, so that it's fine to have two embedded articles which both have a section with an ID #introduction.)