Many people think that the loss of the strange knife process and the loss of training methods are indeed part of the reason for this. But in fact, the fundamental reason is that after the Song Dynasty added Zhao Kuangyin's yellow robe and released the military power with a cup of wine, the Song Dynasty was heavy on literature and light on martial arts.
In the flourishing Tang Dynasty, the martial arts prevailed and the national wars continued, thus targeting the war machine Mo Dao heavy infantry team developed against the many northern nomadic cavalry.
During the Tang Dynasty, the Mo Dao Team was also often the core backbone of the army, not only equipped with expensive Mo Dao, but also required arduous training, which could face off against thousands of infantry troops and horses, and was almost extinct by the Song Dynasty.
The Court of the Great Song Dynasty would not be assured of spending a lot of money and energy to raise such an army on the frontier, not to mention that the appearance of the infantry armor and the crossbow of the Divine Arm made the position of the Strange Sword Troops embarrassing.
The cavalry can attack the Strange Knife Team from a distance, and the Strange Knife Team cannot catch up, the real heavy cavalry Strange Knife Team may not be able to cut it, and the progress of the armor technology makes the Strange Knife Team even more embarrassing.
Both Western Xia and Jin had well-known heavy cavalry, iron harriers and iron floating tu, and the armor at this time was difficult to split except with blunt weapons, so Yue Fei trained troops similar to the Mo Dao team to defeat the Tie Fu Tu, using blunt weapons such as axes, although the mo knives were sharp, they were easy to curl the blades, and the blunt weapons had a better armor-breaking effect.
Therefore, it can be said that the main reason is that the armor and the divine arm crossbow technology eliminated the Mo Dao, and the Song Dynasty's army system of heavy literature and light weapons was difficult to appear and feed such elite troops as the Mo Dao Team.