Is there anybody out there who believes that?
> At this point, it's probably too late, as we're all thoroughly trained to deal with the idiosyncracies of the W3C box model to bother using the CSS hack mentioned in the article to get us back to a sane box model where a box with a width:100px actually renders as a 100 pixel wide box.
There's no hack, it's an official CSS property which switches to the "IE" box model. And considering how useful it is (I've said it in the past, I'll say it again, I've never encountered anybody who thought the W3C box model was objectively superior to the MSIE one, it's just that one was the specified, cross-browser, standard model) I have no doubt whatsoever it will be used. A lot.
That web developers have had to put up with it for the last ~5 years does not matter, it's still cognitive load and it still has to be learned by new developers. `box-sizing` lowers developer cognitive load, it'll get used whenever it can be used.