I am a 19 year old guy, just saying that before I get called a creep. A 20 year old woman that marries a 42 year old rich guy would be provided for and not worry about money, at the same time she would also get to be a rich widow if everything goes well once her husband passes away and it is known that widows do way better than the opposite, she also maximizes her fertility window and the most important thing is that she always feels young compared to him which boosts her ego.

For the guy he would get to basically die before his partner reaches her mid to late 50s (hopefully) which is amazing, the problem that modern society has is that all men are attracted to women in their 20s since they are more fertile, it’s really my main argument here to prove age gaps are biologically optimal, it would make men less depressed, perhaps men would be happier if instead of dating a same age mate at 20 they would stay virgins until 40 and then marry with a way younger mate while also offering the best life quality to women because of their experience in providing. Age gap relationships could be more psychologically optimal than same age ones