Women arent attracted to most men (80/20 rule) an unattractive man cant fulfill any of a woman's sexual or romantic desires in a relationship.

The opposite is true for men. Theyre attracted to most women. In a relationship a man will naturally have his desire for romantic love and sex fulfilled.

In the past men used to compensate for this unequal value of trade in a relationship by being providers now the average man wants to split everything in half. This relationship dynamic is not attractive to women ergo the male loneliness crisis.