Jews are God's people by the Old Covenant. That was not ended. Christians are God's people by the New Covenant
Sorry; you’re wrong. Proof-texting proves nothing. Taken as a whole, the NT and Sacred Tradition unambiguously teach that the Jews are alienated. Jesus warns of this over and over.
The end of your quote, “for the gifts and the call of God are irrevocable”, is not in any English translation I see. In fact it is far from most translations.
Actual is below
4 Who are Israelites; to whom pertaineth the adoption, and the glory, and the covenants, and the giving of the law, and the service of God, and the promises;
5 Whose are the fathers, and of whom as concerning the flesh Christ came, who is over all, God blessed for ever. Amen.
6 Not as though the word of God hath taken none effect. For they are not all Israel, which are of Israel:
The glory, the covenants, the giving of the law, and the patriarchs are clearly all past tense. The service of God was completed as a kingdom in the Old Testament as well. The promises were of Christ to come which the next verse makes clear. This really has no bearing on the many places where Christ rejected the Southern Kingdom of Jerusalem, and those followers of Judaism who reject him which he called followers of their father the devil. The kingdom was taken from them and was never to be returned to them.