The Apostles at Jerusalem recognized the need to settle a dispute. Why did they not simply search the Scriptures?
I’m sure they did. Well, actually, I’m sure they knew it well enough to not need to.
Anyway, because we are not under the Law any more. We are not obligated to keep it to be considered righteous in God’s sight.
Jesus came to set us free, not to put us under the bondage of keeping the Law for our justification.
Sin is still defined by the Law and eating blood was strictly forbidden by it and interestingly, that was one of the four commands that the Holy Spirit and Council at Jerusalem still endorsed.
They didn’t tell us we were obligated to keep the Sabbath, to be circumcised, or anything else but they did reinforce the command to not eat blood.
That is for the church.