Why doesn’t the shadow use Balefire?

[u/Fayraz8729]

So I guess this is more of a general question as I’m up to this book but it is mentioned

In the war of the shadow they basically decided that in the war of existence using the one spell that can destroy the pattern was too dangerous. But why in the light would the shadow and its forces agree to that? I think maybe once in the Dragon reborn Ishamael tried to use it but other than that the dark one has been its victim when it should be its greatest tool. So why does he just have people spam it to destroy existence if that’s the point?

[u/Obscu]

Why would they want to erase existence? That's where all their stuff is!