The context in Romans has been that salvation is by faith, not by works.  This context frames it all.  God has made it so that it isn’t bloodlines, ancestry, human effort, or will power that is the path of righteousness, but it is through faith in him.

This is seen through how God’s salvation came through the son of the promise, Isaac, and not Ishmael.

It is seen how God chose Jacob, the younger brother, over Esau, the older brother, demonstrating it was by his ways and not by human effort or desire.

God is not just.  He is Sovereign.  If He decided that salvation is by faith, that is His choosing.

God is willing to use those slated for destruction to show his power and might to those who will are prepared for mercy.

That salvation by faith means even Gentiles, the non-Jews, are included in His plans.

In fact, the Gentiles who believed in faith which is the plan of God, received the righteousness of God that the Jews missed, because the Jews stumbled on what was right in front of them, that salvation was by faith, not bloodlines.