Because of the increase of female hypergamy, and females obtaining equal freedoms
Many men could get away with being strong, or just doing manly things centuries ago, mainly because looks weren't a large focus of what made a man. A man used to be someone who could provide. Someone who could get things done, take no shit, and make his own.
Now that hypergamy has evolved, and women have their freedoms, the only thing that makes a man in their eyes are good looking features.
This is why men are able to be skinny twinks with 0 muscle mass, or jobless losers, but still land a woman.
You can clearly see why giving w*men rights was a bad idea. Now that they can obtain their own resources, quality men or fathers are no longer needed.
Only men who look good are accepted. Looking good does not = quality father or man, meaning more single mother households. Single mother households do not produce good men, which is why the human race is in the state its in
