Why did Sima Qian write in Historical Records that Emperor Wu of the Han Dynasty did not write about her achievements, but only about his belief in ghosts and gods, so as to live forever?

Sima Qian was honest and never avoided the merits and demerits of the emperor. Although Emperor Wu of the Han Dynasty was in the heyday of the Tang Dynasty, he suffered from repeated wars with the Huns, and suffered huge losses in both financial and human resources. It is reasonable for Sima Qian not to write political achievements. As for Liu Che's belief in ghosts and gods and seeking immortality, the emperor has everything, but the emperor is mortal after all, and he has to experience life and death like a mortal. Therefore, after Emperor Wudi made great achievements, he naturally had the idea of seeking immortality. Sima Qian is unfair and will naturally write. Repeated battles and defeats are not the actions of Sima Qian's ideal emperor, but also his personal feelings, which will make Liu Che less great. (personal opinion)