I was only commenting on the first-party code bloat side of the problem mentioned in the article, and I realize this only addresses a part of it. Asset bloat and third party scripts are entirely different beasts that can only really be tackled on a case-by-case basis.
...with deflating the front left tire a little bit, putting a magnet on the gas cap, folding in the side mirrors.
I think you missed the point of the talk (or didn't read or watch it), and the kind of solution you proposed is mentioned there.
(PS I agree with what you said, though, regarding JS dead code elimination.)