The entire point of the story was that God did NOT want a child sacrifice.

In the historical context of other religions in the region demanding human sacrifices that is the message of the story.

Yes, but then the entire rest of it is all about every other type of sacrifice, culminating with that of God himself on the cross, and the Catholic mass is a continuation of that exact sacrifice.

And almost every other religion also practices sacrifice in one form of the other, so if God exists, the one thing that we can be sure about is that he does expect sacrifice.