Jacob had a very specific dream – no other dream in the Bible has a ladder (apart form Jesus reference to it in John 1:51).
Why did God favour Jacob? He was no leader, something of a “mummy’s boy”, a deceiver and con man. There is no answer. God’s blessing is quite independent for Isaac’s. And he still bargains with God. “If you do this, I will do that.”
But reading it makes sense on a personal level. We might say, “Why should God care for me? The answer is, he just does. As Martin Luther wrote shortly before he died, “We are beggars, that is the truth of it.”