Teyvat Five Hundred Years Ago

I don't know what the author means by writing this kind of fanfic. There is an indigenous protagonist in the background, he still has the Eye of God, and it is written 500 years ago, and nothing has changed, so why write a fanfic? Let alone the human-machine indigenous people. In Teyvat, as long as there is the Eye of God, the fate is determined by the laws of heaven. Even the resistance to fate is written. In my opinion, writing fan fiction requires changes to be interesting to read.