https://www.amazon.com/dp/B08XJSTCYZ
Women date and marry up. It happens in every culture. Men with higher incomes are more likely to be married. In cultures with class divides women are allowed to marry men from higher classes but men are not allowed to marry women from higher classes. Even if you read other threads on AskMen you'll see one from today about whether a woman's job affects her attractiveness and the general answer from men is "no".
Does it happen all the time? No, my mother outearns my father and has always done so, to the point that he was the primary caregiver when I was a baby. But it's consistent enough that it's something that we need to acknowledge.