The only realistic way that I see forward are the ad networks (and this includes Google) setting lower maximum payload sizes for ads. Obviously sites can push back on quality and size but it's a hard metric to track consistently given how ad networks serve things.
The fact is: ad-based model just puts the burden on those most susceptible to advertising. It's similar enough to funding schools through state lotteries in that the money comes from somewhere or the results go underfunded, and if you accept state-run lotteries or anything that looks even slightly like today's ad-based internet, you are talking about a funding source that is deeply and fundamentally unethical.
See also: mobile. You have to totally gameify things to get micropayments to work.
I mean, if you want that for websites, sure... but if you think clickbait is bad now...
On the other hand, micropayment would freeze out poor people.