Why does God choose to have a closer relationship with younger siblings?

Throughout Genesis, God has a close relationship with many of the younger siblings in the stories (e.g., Isaac, Jacob, Joseph). I believe that this shows components of God’s character. These men were all born under interesting circumstances. They were born to women who did not think that they could have many children. None of them actually had the birthright, but they all were chosen to be in the family line that led to Jesus.
I think that God chose these men because they were not the first pick in that society. They would have just had to rely on their older siblings, and they would not have been made great. This just shows that each individual, even though they may start out in a small setting, can become something great. This is really true of Joseph. He was the youngest, and he was despised by his brothers, but he became one of the head men in Egypt, and he helped save his family during the drought.
It also shows that God gives us gifts that may not seem to be helpful, but they can be used for good. I’m sure that Joseph’s dreams were not really respected, and he may have even found them annoying or confusing, but through interpreting those dreams, he became great, and he also predicted the drought, which in turn meant he saved a nation.
In the New Testament, Jesus says that “many who are first will be last, and the last first” (Mark 10:31). I think that in some sense, God was demonstrating this before the birth of Jesus. If God would have chosen someone who was already a strong power, then that person may not have realized the grace God was offering. They could become proud and think it was their own doing that got them where they were.
By choosing people who were not the most well-liked, or strongest, God showed how God can use any person, no matter their abilities. If God gives us the strength, we can do it.