Would a WARC format reduce effort needed to make Reader-like programs? Ie strip pages of HTML cruft, leaving you with text, images, etc - the content?
A WARC file gives you exactly what you would see on the wire, or in the network inspector tab of your browser. It does nothing to the content, and that's the point.
The only thing you gain (and that's very important for other reasons as well) is an immutable ground truth to work from when creating the reader view of a given article.