Nibelung or Heavenly Principles?

Genshin Impact

I've been exploring the Frost Moon and honestly it's been the most fun I've had with Genshin Impact in a while, the tempo of exploration, puzzles and rewards is well structured and just invite you to go more and more deep to learn about it, but I'm starting to be confused about the timeline.

Apparently the dragons on the moon (wait, there were dragons on the moon?!) captured a signal from far away in the space and thought it was a signal from their late king Nibelung and started researching more and more. Some of the researcher instead thought it come from a different creature altogether. I'm speculating the Heavenly Principles that arrived afterward and established order in Teyvat. This means it's supposed to be set between the departure of Nibelung and the arrival of HP in the far past of the world.

Does this mean these facilities have been left there standing since the age way before the arrival of HP? The other two moons were destroyed, but the frost moon was kept intact, but why leave all the facilities running normally for so long? I'm curious to see where this go.

By the way, the fact that they made this world quest voiced made a big difference in my enjoyment, a lot of the old world quests would've gained a lot by being voiced. I remember Kazari in Inazuma being one I cherished a lot.

It all goes back to that signal, was it from Nibelung the king of dragons or from something completely different. e.g. The heavenly principles.
It all goes back to that signal, was it from Nibelung the king of dragons or from something completely different. e.g. The heavenly principles.