What we appear to need are tools and standards to help ourselves cut through clutter

Standards don't help at all unless there's some incentive to follow them.

Currently you'd have a hard time convincing an advertiser to semantically mark it ads, because it goes against the goals of advertising.

There have been lots of proposals for more semantic markup, but none of them have really been successful on a large scale. Why? Because it's extra hassle for the content creator: first you have to learn a new markup format, enter your data in that format, and then turn it back into HTML so that all the browsers in the world can view it again, and in the end nobody ends up using the more semantic version anyway.