Endbringers are subconciously directed by Eidolon.
If humanity were to leave Earth Bet and go somewhere else, they would follow.
Also, we have a couple of months before the new Endbringers appear, whereas doing a thorough exodus to an alternate Earth would take far longer than that.
Unless, of course, you decided to completely abandon everything you had for the sake of evacuating as many people and as quickly as possible.
Since we'll deal with Jack soon, we'll have at least a decade before Scion goes batshit crazy... unless we decide to talk to the Greatest Hero of Earth Bet, and accidentally set him off.
That's why finding out that he's the Big Bad here is crucial.
The second (possibly the first, depending on how things go with Scion) most pressing problem is the presence of Endbringers.
Three new ones came after Behemoth.
We killed Leviathan and Ziz.
Therefore, we'll have to deal with six new EB's.
That's not something you let happen without warning people about it.
If killing two made us the symbol of hope to Earth Bet, then the sudden and horrifying realization that three more EB's will appear every time one is killed, would shatter that hope like glass.
In fact, I wouldn't be surprised if it led to anarchy.
There is a reason why the most efficient ways of breaking people include giving them hope, and then brutally tearing it away.
@sun tzu
Hey, since we read Ziz's mind, shouldn't we know - or at least have a clue as to - who the one directing the Endbringers is?
I think I recall something in Canon that has her 'thinking' about Eidolon, although I don't think she ever uses his name.
Shouldn't it provide a lead?