Wait, I thought that was already the effect, no? With men outnumbering women by a good margin, surely men would try to "out-man" each other to find a mate?
You can't really out-man other men like we used to in the old days anymore.
(i.e. raid another village, kill the men, take the women)
Nowadays we do things more civilized by posing on social media with gym bods and expensive cars and other displays of sexual fitness. Trying to lure a mate instead of taking one.
Unfortunately, the numbers are what they are: a ~30 million gender imbalance. So however you turn it there's going to be 30 million men without a wife/family no matter what they do. Not a good thing if you want society to remain peaceful.
So they either import more women (via force or promise of a better living standard), or they get rid of the excess men (via war), or they suppress them with heavy policing and entertainment doping until the gender imbalance fades out over the next generation or so.
When there are so many men that they know that they will never have a girlfriend or wife in their lives, they stop competing....why go to the gym at that point?