[atomicfiredoll]

If we've concluded that's it's okay to have elements that change/morph, as we seem to with the introduction of things like details, a native tab-like element feels like a glaring omission. Tabs have been a long-standing UI pattern and forcing every site to implement their own is a nightmare for accessibility. (The page you're reading is maybe already in a browser tab.)

I wouldn't be surprised if it turned out less than half of the custom tab interfaces on the web failed from an accessibility standpoint. When considering ARIA guidance, I don't even think it's possible to build an accessible version in HTML alone.

Other people have recognized it's missing. Open UI has a draft spec for it[0] and CSS Tricks has an article from 2001 about Open UI's experiments with sections for tabs[1]. I have no idea what happened on this front, though.

[0] https://open-ui.org/components/tabs/

[1] https://css-tricks.com/newsletter/281-tabs-and-spicy-drama/