Sure, women’s physical attractiveness usually decrease, but The Wall is first and foremost both the sense of urgency women feel to settle, due to society’s pressure and the (rarer as time goes by) desire to build a home and have kids. 30 year old are still super attractive and can still attract top quality men, the competition is simply more intense.

The other part of this is male’s maturation. By the time women start to hit the proverbial wall, men, even previously socially inept ones, have grown more confident and interesting, the balance is sort of restored.

So talking about the Wall as some kind of expiration date for women is wrong and come from stupid revenge fantasy. It’s simply a convergence of value of the sexes