Yue Fei has experienced many battles, big and small 100, and rarely lost. From the age of 19, Yue Fei joined the military camp until he was 38, when Yue Fei defeated Ren Jin. His brilliant exploits won a rare respite for the Southern Song Dynasty, which made the crumbling Southern Song regime a little more stable. Zhao Gou knows what he has done, but Zhao Gou still can't help him, because he doesn't know if Yue Fei will launch a second mutiny in Chen Qiao, and he knows how he got his hands on Zhao.
So, in order to avoid complications, he had to get rid of Yue Fei. At that time, Yue Fei had too many mercenaries, and almost all the imperial troops were used by him. Although Yue Fei was not rebellious at that time, Zhao Gou did not dare to take the risk. In his view, only when Yue Fei is gone can he feel at ease.
Another thing to mention is that the Song Dynasty is a dynasty that values literature over martial arts, so a military commander like Yue Fei will not be reused after the world is at peace. After the war was settled, Zhao Gou immediately removed his relieving power, but even if Yue Fei lost the relieving power, his prestige still existed. So Zhao Gou had to very reluctantly give up what one favours, extermination. Because he must put an end to all uncontrollable factors, and Yue Fei is the biggest threat to him among these many factors, and he must cut it quickly in order to sit back and relax and be an emperor.
Yue Fei's life ended in tragedy. He worked hard all his life, but it didn't end well. Yue Fei himself knew why Zhao Gou wanted to kill him. He also knows that Zhao Gou was forced to do so. He also understood why Zhao Gou did this, but Yue Fei was too patriotic and loyal, and never chose to resist.