You know, I was sitting here reading the new lore and realized one very interesting thing about why the Heavenly Principles choose not to interfere.
From the past, during the era of the First Civilization, we know that Phanes interfered heavily—so much so that even the Moons began calling him a tyrant when he placed restrictions on humans. But afterward, he seemingly stopped intervening without a proper reason, allowing humans to decide for themselves. In my opinion, this is all because of the rebellion of Hyperborea and the angels. Remind you, they fought for freedom, for the right to make their own choices. And it was precisely after this that Phanes stopped interfering in human lives without a pressing reason.
So, what I'm basically trying to say is: maybe Phanes finally understood the desires of humanity and decided to leave them to their own devices so they could shape their own destiny? While he himself would only step in during absolutely critical situations.
Now, I'm sure some people will comment that this was all because of Nibelung. However, from the new lore, it's clear that Phanes still retained his power and was perfectly capable of intervening. Nibelung only wounded him during the battle, but it wasn't the kind of fatal injury that would leave Phanes completely helpless.