In western society women generally marry across or up, and men generally marry across or down.

In my opinion this is driven by natural female hypergomy, men usually have little concern for their mates socio-economic status and are more focused on biologocal fitness.

So hypergomy together with a drop in male performance (less education and lower job prospects than in the past) is resulting in a growing pool of woman trying to find an acceptable mate from an ever shrinking pool of eligible men.

To further aggravate the situation the men in the higher status pool are acceptable to a very large pool of woman, and as I said men are concerned with biological fitness which means the younger, fitter and healthier a woman is, the more attractive she is.

Understandably it takes time to complete collage and develop a career which means that woman are now usually a little older when they start looking to settle down, but, the men they want to settle down with are generally settled already or looking for younger woman further reducing the size of the pool of availible high status men.

None of this is a value judgement, this is natural behaviour and is playing out a little differently for men, look at Japan with their 'Herbivore Men' or 'MGTOW' who are reacting to the same pressures.