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 much of a reason to fix it on their own.