The author seems not to know what a codpiece is, as if he thinks it's an unneeded extra garment men wore on top to draw attention to their genitals.
Mens' trousers in those days were two separate garments: a left leg and a right leg. It's why we still say "a pair of trousers". You needed a codpiece to cover the gap in the middle, and it would also help hold your trousers up.
Peasants didn't need to bother with all this stuff as they could not afford trousers and would just wear a dirty tunic like a sack.
Then someone invented modern trousers that are one garment and the codpiece was not needed any more.
Mens' trousers in those days were two separate garments: a left leg and a right leg. It's why we still say "a pair of trousers". You needed a codpiece to cover the gap in the middle, and it would also help hold your trousers up.
Peasants didn't need to bother with all this stuff as they could not afford trousers and would just wear a dirty tunic like a sack.
Then someone invented modern trousers that are one garment and the codpiece was not needed any more.