Worse, it has changed content rules and semantics in backward-incompatible ways. Meaning there are pages out there that used to be valid, but aren't anymore. And since HTML spills to EPub specs, I recall there were EPubs or EPub spec examples/test suites themselves having to change specifically, epubcheck being actually used for validation and hence directly noting this backward incompatibility.
In a nutshell, hgroup was originally criticized and rejected when W3C was still redacting HTML specs received from the loose group of browser devs and other people calling themselves "WHAT working group" because it paired headings of multiple ranks in a way that confused assistive technologies in browsers. But the first (and at the same time the last;) W3C HTML recommenndation created as unredacted WHAT WG spec snapshot under the W3C/WHATWG "memorandum of understanding" actually smuggled hgroup in. Then Steve Faulkner removed HTML outlining and the whole concept of sectioning roots that was part of Ian Hickson's vision of "HTML 5" for the longest time, but W3C never actually started a new recommendation process afterwards, and the charter for the HTML WG at W3C, Inc. has ended last year. See details at [1].
Arguably, with this change in 2023, we're now post-HTML5. But don't tell the people believing in a single "HTML 5 standard".
unlike the <blink> tag where younger people will just stare at you in a creepy extended unblinking gaze. it would be so much more satisfying if it still made them blink.
