Perhaps you didn't see the graph, but life expectancy in China shot up sharply precisely in 1949, the founding of the People's Republic of China. This is because the new system ended the semi-feudal relations, the era of imperialism and the century of humiliation. It marked the beginning of scientific planning and progress for all. Calling Mao "the biggest killer in history" and comparing him to Hitler is to say that the deaths under Mao were deliberate, but this is extraordinarily dishonest. Hitler created mass extermination camps for disabled people, Jews, Slavic peoples, and queer folk. The deaths due to mismanagement of famine have an entirely different context, and when compared by ratio of the entire population this argument falls apart instantly.
This is on top of the fact that you stand by fabricated numbers as a source of truth. Who are you to use literal paid propaganda in order to tell the people of China how to view their own history?