As a consultant, I only see web site producers making an effort to curb poor web practices when Google forces them to: Google's move to boost mobile-friendly design in the rankings has driven us a TON of responsive design work. I wonder if that is going to be what it takes to fix today's bloat problems: Google takes the hammer to sites that too much advertising cruft. Otherwise, I don't see business makers seeing muc…
That could get interesting: Google, using the argument that all those ad-related scripts make things slow, ranking sites with a lot of them lower than sites which don't, and at the same time hitting their competitors hard: after all, Google makes money through ads, if their competitors are forced to be used less (by Google's own actions) more people might be using Google ad networks.