Why is it that the Xia Dynasty may be a legendary existence, but it is not true?

There is a jingle in the ancient history of China, which begins with the following words: Tang Yao, Yu Shun, Xia, Shang and Zhou Dynasties, Spring and Autumn Warring States, Qin and Han Dynasties, and the Southern Dynasties and the Northern Dynasties were rivals ... This jingle has made the source of the Chinese nation start from the Three Emperors and Five Emperors, and then spread to the Xia, Shang and Zhou Dynasties. We often say that we are an ancient civilization with a history of five thousand years. The five thousand years here are counted from the Three Emperors and Five Emperors, and from Tang Yao and Yu Shun.

Although our textbooks regard the Xia Dynasty as the first dynasty of Chinese civilization, there is no archaeological evidence. After a hundred years of archaeology and decades of large-scale land acquisition and development, we can't find any clues about the existence of Xia Dynasty. In fact, Erlitou is the same period as Shang Dynasty, and Erlitou culture is only a very primitive tribal cultural site, not a "civilization".

Many people denied the existence of the Xia Dynasty, but a large number of bronzes unearthed since then proved that the Zhou regime did exist in the history of China after the Shang Dynasty. Through the study of these unearthed cultural relics, we find that the Shang and Zhou Dynasties were inherited. The so-called inheritance is not only that one regime replaces another regime on the same land, but that the culture between the two regimes is continuous.

Before the Xia dynasty, it had a history of about 4000 years. Because of its long history, we haven't found any original documents and records. So many people doubt whether there is a history of the Xia Dynasty. In recent years, we have a new understanding of the development of politics, economy and culture through the study of the Zhou Dynasty Chronology Project. From this point of view, from the excavated sites, the Xia Dynasty has entered the Bronze Age of Neolithic Age and mastered metallurgy and casting technology, so the Xia Dynasty exists, but it has not been systematically excavated.