I got a little curious on the statuses of these standards and went on a bit of searching.

- CSS contain (CSS Containment Module Level 2) - Editor's Draft[1]. First published in 2019. Not supported by Safari/WebKit.

- CSS offset-path (Motion Path Module Level 1) - Editor's Draft[2]. First published in 2015. Not supported by Safari/WebKit.

- CSS overflow-anchor (CSS Scroll Anchoring Module Level 1) - Editor's Draft[3]. First published in 2020. Not supported by Safari/WebKit.

- Resolution media queries (dppx) - W3C Recommendation since 2012[4]. Not supported by Safari/WebKit.

- :focus-visible (Selectors Level 4) - Editor's Draft[5]. First published in 2011. Not supported by Safari/WebKit.

- Touch Events - W3C Recommendation since 2013[6]. Supported by Safari/WebKit since 2010 (iOS 3.2). I assume the author meant Pointer Events[7] which became W3C recommendation since 2019, and supported since 2019 (iOS 13.2).

- BroadcastChannel - WHATWG Living Standard[8]. Blocked by privacy concern on WebKit side since 2020[9]. Initial support landed on WebKit trunk as of 2021-07[10].

- beforeprint/afterprint - WHATWG Living Standard[11]. Supported by Safari/WebKit since 2019 (iOS 13).

- Regex Lookbehind - ECMAScript 2018[12]. Not supported by Safari/WebKit.

- scrollIntoView (CSSOM View Module) - Editor's Draft[13]. First introduced as an update to CSSOM View Module in 2011. Not supported by Safari/WebKit.

- Screen Orientation API - W3C Working Draft[14]. First committed in wc3/screen-orientation in 2012. Not supported by Safari/WebKit.

- Date and time input types - WHATWG Living Standard[15], partial support by Safari/WebKit since 2012 (iOS 5) but no week/min/max.

- Service Workers - W3C Candidate Recommendation since 2019[16]. Supported by Safari/WebKit since 2018 (iOS 14.5).

- AbortSignal - WHATWG Living Standard[17]. Supported by Safari/WebKit since 2018 (iOS 11.3)

- Intersection Observer - W3C Working Draft[18]. First published in 2017. Supported by Safari/WebKit since 2019 (iOS 12.2).

- Client-side form validation - WHATWG Living Standard[19]. Supported by Safari/WebKit since 2017 (iOS 10.3).

[1]: https://drafts.csswg.org/css-contain/#contain-property

[2]: https://drafts.fxtf.org/motion/#offset-path-property

[3]: https://drafts.csswg.org/css-scroll-anchoring/#exclusion-api

[4]: https://www.w3.org/TR/css3-mediaqueries/#resolution

[5]: https://drafts.csswg.org/selectors-4/#the-focus-visible-pseu...

[6]: https://www.w3.org/TR/touch-events/

[7]: https://www.w3.org/TR/pointerevents/

[8]: https://html.spec.whatwg.org/multipage/web-messaging.html#br...

[9]: https://github.com/whatwg/html/issues/5803

[10]: https://bugs.webkit.org/show_bug.cgi?id=227924

[11]: https://html.spec.whatwg.org/multipage/timers-and-user-promp...

[12]: https://262.ecma-international.org/9.0/

[13]: https://drafts.csswg.org/cssom-view/#dom-element-scrollintov...

[14]: https://www.w3.org/TR/screen-orientation/

[15]: https://html.spec.whatwg.org/multipage/input.html#date-state...

[16]: https://www.w3.org/TR/service-workers/

[17]: https://dom.spec.whatwg.org/#abortsignal

[18]: https://www.w3.org/TR/intersection-observer/

[19]: https://html.spec.whatwg.org/multipage/forms.html#client-sid...