People should stop comparing apples and oranges as there are various types of age gap relationships with a huge difference in dynamics.

Despite second one being literally 3 times bigger numerically, the first one includes a graduated guy that works and a high school girl, while the second one includes two people that graduated, have work and if a girl is marriage oriented she might not care about age difference or even prefer an older guy since she might have already been in a relationship or two and got burned by a guy her age with similar or somewhat higher SMV who "wanted to live". If she wants it serious an older guy might be a better bet even if the difference is bigger than 10 years. There is nothing "predatory" in that case as both sides have their own interest in that relationship.