Now compare this to Instant Articles spec: <a href="https:&#x2F;&#x2F;developers.facebook.com&#x2F;docs&#x2F;instant-articles&#x2F;reference" rel="nofollow">https:&#x2F;&#x2F;developers.facebook.com&#x2F;docs&#x2F;instant-articles&#x2F;refere...</a>
No JS, no Custom Elements, just pure HTML.