The history of the mid-Xia and Zhou Dynasties is relatively short, after all, it is too long. Like Huangdi and Yan Di, they appeared in history books mainly because of Taishigong's books, and their family history was also mentioned in the notebooks of the Five Emperors. For example, the founding monarch of the Zhou Dynasty said that he was a descendant of the Yellow Emperor because his surname was Ji. As for them, this thing is probably left by our great ancestors, which is what we call a myth. It is also their understanding of natural forces, or for political purposes, such as seeing how awesome the Yellow Emperor is. My ancestor is the Yellow Emperor, so I am also more awesome, and I can command the princes of the world.
Of course, you can also see something. For example, the goddess of mending the sky was flooded, which is also recorded in the myths of other countries, indicating that there may really be floods on the earth during that time.
You can also choose to believe these myths. For example, they are caused by people who are more advanced than us, and their walking is possible in modern times. Who knows if it will be better in the future? Or someone from Cybertron has been there. Have you seen Avatar? Maybe a group of people have been here in ancient times, so it is impossible to call us Na 'vi. Look at your own understanding of history!