As female hypergamy becomes more extreme more men will continue to no longer have marriage prospects thus have no families. Men with no families contribute significantly less than men who do have families. The collapse will be drawn out as men slowly realize they will never have families and thus no longer put effort into society. Industries will collapse, birthrates will fall, and finally one day things will devolve into chaos where gangs and other criminal groups will have control all of everything similar to the situation in current day Haiti or Somalia. The only way to prevent this is to bring back the practice of arranged marriage.