The final sacrifice they intended to make to Zodiark of lesser life forms would have liberated the human souls inside of him, returning them to a now stable planet. Basically a happy ending for humanity at the cost of life forms that were not their equivalent. Venat decided to get in the way of that and stripped the remnants of humanity of their immortality, changed their physical forms beyond recognition which forced them to evolve into the different spoken races, and left the others trapped within Zodiark with no means of escape.
Perhaps if she didn't do that they could make new concepts to send to fight Meteion, but alas she decided to become Hydaelyn and sunder the star instead because of her "fear" of the Plenty. Again, those of us who played through the Elpis sidequests aren't all that convinced that they would suffer that kind of fate because the Ancients are very much portrayed as a people who are good at keeping themselves busy. They had problems of their own and rather than seeking "comfort" their work seemed to focus moreso on functional additions to the world. They weren't trying to erase their pain, they were trying to figure out food chains and that sort of thing.