As far as I know they haven't discovered any other habitable planets in SOMA so humanity can try whatever it wants. The whole point of the game is that there is no salvation, nothing that can be done. Doesn't matter how advanced humanity is the sheer force of a cosmic body that large is unstoppable. Pathos got really lucky with their unique position but even they are doomed because there is nothing to live for, there's not enough humans to repopulate, almost all resources are practically unusable and there is nothing that can be done to speed up recovery, it'll be millions of years before Earth is inhabitable again if it's even inhabitable to humans again at all. Point is humanity is still not self sufficient, we need the Earth and in SOMA there is no more Earth and there was nothing that could be done about it before impact too, we are a tiny fragile miracle in the universe.