Why didn't Zhuge Liang revive the Han Dynasty?

First, it is difficult to go to the sky.

It is difficult for the army to transport grain, and it is easy to run out of grain and grass at the front. To attack Wei, it is much faster to take it from Chang 'an first, but the road to Chang 'an is rugged and difficult.

Second, although Shu is a battleground for military strategists, it is short of talents. Zhuge Liang killed Ma Su with tears in his eyes, actually because Ma Su was a really scarce talent in Shu. Losing Ma Su is a great loss for Shu, and Zhuge Liang is heartbroken!

Third, the late Liu Chan was incompetent and listened to rumors. When Zhuge Liang went out of Qishan for the fourth time, Gouan was beaten eighty times by Zhuge Liang's aides because of drinking on the way, so he held a grudge and surrendered to Wei Jun. At that time, Wei Jun was losing ground, and Sima Yi sent Gouan to Chengdu to spread a lie that Zhuge Liang was self-reliant and would usurp the country sooner or later. After hearing this, the late Lord sent Zhuge Liang back, but he gave up halfway.

Fourth, the greatest enemy of Zhuge Liang's Northern Expedition was Sima Yi. He was wily and secretive, like Zhuge Liang, and he also had his own unique vision in military politics, but Sima Yi was very cautious, especially in treating people like Zhuge Liang.