The boys who insist on pretty or rich would rather stick around for the next year’s pretty and rich girls than take this years other girls. So the rich and pretty girls are desired by more than one year’s worth of boys. That’s why there are “less” girls for more boys. If boys would still insist on only rich and pretty than closing the age gap would help nothing. They would still rather wait around for next graduating class to choose rich and pretty than take something else. So having boys date younger wouldn’t change anything as long as they still have screwed on priorities. I cannot even print what one shadchan quoted to me from the “great Lakewood boy” she was inquiring about my friend for, of why he needs someone skinny. The girls are taught to look for tochen, and to seek to develop their inner qualities and the boys both look for external and overly value external.
Maybe there’s a reason you have to keep repeating yourself for four years: where’s the proof that the population grows so exponentially from one YEAR to another YEAR. Perhaps there’s a reason so many people are still so skeptical about this theory.