"Romans 9 is referring to individual election of temporal and material blessing. It is not referring to election to salvation."
To make this argument, you must ignore the entire context of Romans 1-8 which is all about salvation by faith appropriated by the individual.
In fact Romans 8 is where Paul introduces the concept of predestination:
"For those whom he foreknew he also predestined to be conformed to the image of his Son, in order that he might be the firstborn among many brothers. And those whom he predestined he also called, and those whom he called he also justified, and those whom he justified he also glorified." (Romans 8:29-30)
We were chosen by God before we were born.
We were chosen so God’s purposes will stand.
We were chosen not based on man’s works or will -
but based on God’s sovereign free will to extend mercy. (Romans 9:16)
Because all men are sinful and deserve God’s condemnation, no person is wronged or treated unjustly if God chooses to condemn him.
For God to condemn sinners is not injustice.
That is justice. Justice is good. Mercy is good.
God choose who gets justice and who gets mercy.
With God, no one gets injustice.
“Why did God choose Jacob, not Esau?”
Answer: God chooses to whom He grants mercy not on the basis of man’s will, but based on God’s sovereign free will so that His purposes might stand. And that divine prerogative is what makes Him God.
Why Did God Choose Jacob, Not Esau?