If stores using microformats and semantic markup is important then give value added to the places that support it and people will start using. If readability is important start penalizing sites with bad readability indexes. But please don't take over my UX. I can't think of a faster way to stifle innovation.[1]
Try the documentation, much less political https://mozilla.github.io/fathom/intro.html#why
[1] That's an exaggeration. I can think of lots of better ways.