I think you're missing the OP's point though.
It's true that you can just use some CSS to make up for the lost HTML feature, but than again you could also rewrite the HTML part.
Forgive me if I'm wrong, but I'm fairly sure that what the OP is trying to say, is that there are plenty of great websites out there, which were developed a long time ago, and for which there is no maintainer to do any work on it. Thus having HTML elements like this dropped, would make the content in a way lost.
Thinking about it some more, users can probably add plugins to add this css automatically, or some browsers might even keep those features in, but still, there will be users that don't know this, I think, resulting in a bad experience.