1 Geographically, Shu Han only occupied Yizhou at that time, and Cao Wei occupied Qingzhou Youzhou in Jizhou and Yongzhou Liangzhou in Xuzhou Yuzhou. Moreover, Yunnan-Guichuan, where Shu Han lived, was blocked in traffic and backward in economy, and could not compete with the Central Plains at that time.
Economically, although Sichuan Basin, a land of abundance in Shu and Han dynasties, can produce more grain, it can't afford years of war, and even the people become more delicious (hungry people are everywhere). However, Cao and Wei practiced the system of reclaiming farmland, and the relations of production were adjusted, and the grain output was enough to supply years of wars.
Politically, Jingzhou Group, the ruler of Shuhan, and Ada's old group in Liuzhang oppressed the indigenous people of Shuhan, making them dissatisfied with the ruler of Shuhan. Liu Chan, the emperor of Shu Han, was quite fatuous, and some traitors were in power. However, Cao Wei adopted the system of "Nine Kinds of Righteousness", which was supported by a large family and had a relatively stable rule. Sima Yi, the third ancestor of Cao Wei and his minister, was also very clever.
Militarily, Shu Han Serenade, about 100 thousand, more than a dozen generals outstanding; Cao Wei led millions of troops, 10,000 floating boats, more than 1,000 war generals, and 30 to 40 outstanding people. Shu Han can't compete with Cao Wei.
In terms of talents, Liu Bei and Zhuge Liang, the leaders of Shu Han, have not done a good job as successors, and their children are of great use; Cao Wei, Cao Pi, Cao Rui, Sima Yi, Sima Shi, Si Mazhao and other talents were not at fault.
Shu Han's goal is to help the Han family. He has lofty ideals, but many of them are unrealistic. In addition, years of war exhausted the national strength of Shu Han.