During the Warring States Period, Chu had the largest territory. Why was the Chu army’s combat effectiveness so poor?

I think there are two reasons. One is that the combat effectiveness of their army is really bad, and the other is that King Chu Huai is really mentally retarded and cannot give correct military guidance at all to make the army strong. I don't know where to use it, and I can't show my strength at all.

First of all, although the area of ??Chu State was the largest among the vassal states at that time, the number of people in Chu State was not the largest. It was a vast land with sparsely populated areas, and the resources were not the most abundant. Moreover, the Chu State during the Warring States Period had passed its heyday. People had experienced an overly comfortable life. The domestic ruling class was extremely corrupt. Most of the military children joined the army for fame, and few had the ability to march and fight. Therefore, the Chu State It is conceivable that the combat effectiveness of the troops is weak.

Secondly, Chu’s weak combat effectiveness is inseparable from King Huai of Chu’s mediocrity and incompetence. If the person in power of a country is deceived by other countries and believes everything they say, and cannot make any decisions that are beneficial to the country, how far can the country be from being destroyed? At that time, King Huai of Chu mistakenly believed in Qin's lobbyist Zhang Yi, destroyed the Qi-Chu alliance, and gave up Qi's powerful arm. He also trusted the sycophants and forced Qu Yuan to commit suicide in the Miluo River. He lost his loyal ministers and doted on Mrs. Zheng. He lived in the harem and indulged in debauchery and ignored political affairs. In this way, no matter how strong the combat effectiveness of the Chu State's army is, it cannot be exerted without correct military decisions, not to mention that the Chu State's military strength is not very strong in the first place.

So although the Chu State is the country with the most land, it is not the country with the strongest military strength. Coupled with the blessing of the incompetent monarch, King Huai of Chu, it seems that the combat effectiveness of the Chu State is even lower, which also makes the Chu State even lower. People felt that the demise of Chu State was a joke.