Originally Posted by
Veloran
So aether consumption was the cause of the Final Days, which the planet sought to rectify by eliminating huge quantities of aether by leaving the world a barren wasteland, which the Convocation halted by sacrificing huge amounts of aether, which they also contributed to by sacrificing huge amounts of aether, which was solved by Hydaelyn consuming a huge amount of aether to be summoned, which has somehow never reappeared again despite entire Umbral Eras being caused by the mass siphoning of aether from the land?
And this is all ignoring that the Ancients used their own personal aether for creation magic to begin with, not the planet's aether. Also, a better explanation for the towers already exists, namely that instead of them beaming aether from the planet to Zodiark, they're beaming aether from Zodiark to the planet, hence the tempering (I don't think this is exactly correct, but it's more mechanically sound based on what we've seen them do than the opposite).