There doesn't need to be a correlation between some data structure and its effects for people to implement some sort of feature. There only need to be enough stupid people in powerful positions that believe in some sort of correlational trend AND also for the data gathering task to be trivially cheap enough for them to implement said things. And there's no shortage of that going around. That's why these technologies are dangerous. Stupid people with powerful and cheap tools to weald them. Kind of like what we saw with the first wave of Facebook algorithms being used against its users to maximize the attention at the detriment of everything else.