First of all: from Wu himself.
Sun Xiu is the third emperor of Wu after the founding of the People's Republic of China and the sixth son of Sun Quan. Today we look at Sun Xiu's talent from three aspects. Politically, Sun Xiu has made some achievements. After he succeeded to the throne, with the help of ministers Zhang Bu and Ding Feng, Wu Dongsun Chen Group was eliminated and the civil strife in Wu Dong at that time was quelled. However, Sun Xiu's excessive trust in this man led Zhang Bu and Puyang Star to control the political affairs in Wu Dong, which laid many hidden dangers for the later Emperor Wu Dong. Militarily, when Sun Xiu was in power, Wu Dong had no ability to expand. Until Shu was destroyed, although Sun Xiu sent five troops to help Shu, they all failed. Culture: Sun Xiu attached great importance to education and farming, and made some contributions to the talent selection system. Based on the above three factors, at this time, the state of Wu was in its twilight years, many famous soldiers died young, and the internal affairs in the later period were turbulent, which doomed the situation of national subjugation.
Secondly: from the perspective of Shu.
When Sun Xiu ascended the throne, Zhuge Liang of Shu died 12 years ago. The military activities of Shu were always controlled by Jiang Wei, a general at that time, and the policy of Shu was always both offensive and defensive. In addition, there were many famous soldiers loyal to Shu in the later period of Shu, which completely attracted Wei's strategic focus to Shu. It can be said that without the restraint of Shu, Wu could not have persisted for so long, which is the strategic goal of Liu Bei and Zhuge Liang to divide the world into three parts in Longzhong.
Finally: From Wei's point of view.
At this time, Sima Yi has been dead for seven years, but Sima Jia has completely mastered all the power of Wei. Whether it is land area, military strength or talent system, Shu can't compete with it. Unification is only a matter of time.
If you have any better ideas about the above things, please write them at the bottom of the comment area and we will discuss them together.