For the most part, jQuery was absorbed into ES/JavaScript, not HTML.
Well yeah, that's still under "browser standards."
The difference is that the internet can exist (and did) quite well without JavaScript. Without HTML there is no internet. Furthermore, ECMAScript is a language and W3C/WHATWG are a consortium that maintain HTML.
Sorry to nitpick, but there is a lot more to the internet than the web.
The most visible part of jQuery for me was always querying selectors - $('.some > a.selector'); and that certainly was something integrated into HTML/the DOM as document.querySelectorAll('.some > a.selector').
And the browser APIs still have significantly worse ergonomics than jQuery