If you consider sin as creating a "debt" with God, then God pays our debt Himself.
Still, I prefer the image of sacrifice as a symbol of reconciliation with God to one of placating an angry God.
It's not a question of anger, just that justice requires debts to be paid.
The Crucifixion allows suffering, of which the world is full, to finally have some meaning. Or, if not that far, at least we can understand that suffering is something that even God did not excuse Himself from. Had God simply erased the debt rather than paying it, we would have a very different message put out.
SD
In the face of our repentance, God could simply say "I forgive you".
I said, "I will confess my transgressions to the LORD";
then thou didst forgive the guilt of my sin. (Psalm 32:5)
Why the need for Jesus to die for this to happen?