Paul said James was an apostle.
Galatians 1:19 But other of the apostles saw I none, save James the Lord's brother.
Do you believe Paul?
Why would I continue to follow Jewish leaders when Jesus had put the Apostles in charge?
Gee that's funny. I thought all the apostles were jews.
And there were 13 successors and blood relatives of the Messiah as head of the Church until 135ad.
Go on believing that.
Why should I not? Did Heggisipus and Esuebius lie?
Duh.
Gee that's funny. I thought all the apostles were jews.
But not "Jewish leaders" meaning leaders of the Jews, the priests and the scribes, etc. Don't act stupid.
You would rather behave as a Jew than accept the leadership of the Church. You don't like what became of it, so you fantasise that God failed in protecting the Church from error.