Why didn't Empress Dowager Ying Zheng want to delegate power and return power?

Many netizens said that Dafuqin should be renamed Ying Zheng's Road to Pro-government or The Legend of Lv Buwei. Ying Zheng succeeded to the throne at the age of thirteen. The late king left the Empress Dowager to supervise the country, and the Prime Minister was in charge of state affairs until Ying Zheng became weak in the crown. But when Ying Zheng was twenty years old, Empress Dowager Zhao refused to delegate power. It's too hard for Ying Zheng. His mother and Guan Zhong are in charge of state affairs. If they don't want to regain power, Ying Zheng's road to governing the country will be far away. I'm curious about how Zheng Can led this country in previous episodes. He attaches great importance to Reese to prepare for leading the country. Under the careful planning of Reese, Ying Zheng finally grasped the power of Qin State and began to realize his ambition of reunifying the whole country.

Ying Zheng's personal rule should be around forty-five episodes. Historically, he began personal rule at the age of 22. In the eighth year of Ying Zheng's succession, there was a fierce political struggle in the imperial court. When Gao led an army to attack Zhao, he defected and surrendered to Zhao halfway. The following year, 22-year-old Ying Zheng held a coronation ceremony and officially took charge. At the same time, Lao Ai revolted, stole the imperial seal of the King of Qin and the Empress Dowager, and attacked Ying Zheng's residence.

Because Lao Ai was given to Empress Dowager Cixi by Lv Buwei, Ying Zheng was relieved of the post of Prime Minister of Lv Buwei and exiled to Bashu. Finally, Lv Buwei committed suicide by drinking poisoned wine. In Dafuqin, Empress Dowager Cixi and Lv Buwei didn't want to go back to Ying Zheng. They found many excuses to refuse Ying Zheng's pro-government, so Ying Zheng asked Reese to think of countermeasures. Reese said that only by grasping the handle of the Empress Dowager and Xiangbang can the King of Qin lead the government smoothly.

Reese learned that Lao Ai and Empress Zhao Xian had two sons, and Lao Ai used to be the shed of the Prime Minister's Office and was sent to the harem by Lv Buwei, so this incident could make Empress Dowager Zhao and Lv Buwei have to return the government to the king of Qin. Empress Dowager Zhao and Lv Buwei are unwilling to return to power, on the one hand, for Daqin, and on the other hand, for themselves. They have been tempted by power, how can they give up power easily?