Plague weather in northeast China
So Li Zicheng was so easy to succeed at that time because the plague helped him a lot. Because of a plague, basically the whole city of Beijing collapsed. At this time, when Li Zicheng came to attack the city, victory was inevitable, and it was easy to win the city, so Li Zicheng was very happy at that time. After all, winning this city means winning the whole world.
And he thought that as long as Chongzhen died, he could be emperor himself, but Chongzhen was still waiting for Wu Sangui to come to the rescue, but he didn't wait. Therefore, even though Chongzhen is full of talents, it can't stand the demise of the Ming Dynasty. Moreover, when Chongzhen was in power, he was either a disaster relief or a bandit. It was good for the people, but such talents still could not escape the demise of the country.
So Chongzhen didn't want to die of humiliation, so he broke it with a white silk. In fact, there are still many reasons for the demise of the Ming Dynasty. If there had been a rat infestation, it is estimated that the country would have been destroyed so soon. Although the Ming Dynasty collapsed at that time, it would not be so vulnerable, but it was a rat plague that helped Li Zicheng.