Maciej is definitely one of the people whose absolutely dab smack on with his criticisms. Bloat, tracking, annoyances, poor design. Most are a direct consequence of advertising-based content support.
I'm thinking of a Reader-Mode browser, period.
Stock stylesheets. Ignore the site's styles. Maybe provide various themes for the user. Further heuristics to strip other cruft. And a "mercy killing" mode which simply abandons all native markup and presents a page stripped of everything, if it's sufficiently bad.
Say the green text on blue background, with every paragraph individually absolutely positioned, centered justification, H2 headings used for body text, and Microsoft "smart quotes" throughout. I've seen all this (though perhaps not quite all on the same page).