Also, if there is going to be monetization via advertising, why does it have to be a blind auction controlled by an algorithm driven by CPM with a huge cut goin

Also, if there is going to be monetization via advertising, why does it have to be a blind auction controlled by an algorithm driven by CPM with a huge cut going to Google? I wonder what would happen if the major publications collectively decided to switch to impression-based rather than click-based metrics.