Originally Posted by
KizuyaKatogami
Just like how the final days decimated not just a couple continents, but the entire world. What other choice did they have but to summon Zodiark? Did they rely on him? Yes. But it literally isnt any different from how people rely upon the WoL, or how we ourselves are constantly relying on higher up entities to help us. We're shown in the short story that they actually do eventually choose to live on, along with Midgardsormr i believe. So it was very much possible for them to continue through instead of erasing an entire timeline of people to resurrect one person.