This is actually an interesting rabbit hole. Their other constraint is that they are trying to be transparent and fair, for some definition of that word. They n

This is actually an interesting rabbit hole. Their other constraint is that they are trying to be transparent and fair, for some definition of that word. They need that for Section 230 protections, they need it to fend off antitrust lawsuits, etc. So, there is a huge problem with hiring experts and telling them to make subjective decisions. Instead, Google publishes guidelines for webmasters and then enforces them rigidly. This usually ends up penalizing some good sites, while spammers swiftly discover workarounds.