There was a period before the destruction of the temple and Jerusalem, where Jewish believers kept the old covenant law. That's normal and Jewish believers in Messiah, who had lived their whole lives keeping the Sabbath, abstaining from pork..etc, didn't have to reject that. Nonetheless, in Christ, both Jew and Gentile comprise Israel. We who are born again, in Christ, are Israel, whether we identify as Jewish or not. The scepter passed from earthly Judah/The Type, to actual Judah/The Lion Of Judah, who sits on the thrown of David/throne of YHWH in heaven.
While I agree with much that you say...
Take a look at the following prophecy.
Jer 33:15
In those days, and at that time, will I cause the Branch of righteousness to grow up unto David; and he shall execute judgment and righteousness in the land.
Jer 33:16
In those days shall Judah be saved, and Jerusalem shall dwell safely: and this is the name wherewith she shall be called, The LORD our righteousness.
Jer 33:17
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For thus saith the LORD; David shall never want a man to sit upon the throne of the house of Israel;
Jer 33:18
Neither shall the priests the Levites want a man before me to offer burnt offerings, and to kindle meat offerings, and to do sacrifice continually.
Obviously today, Judah is not saved and Jerusalem does not dwell safely.
This is speaking of Christ's return.
We know this further, because at His return, and only then "David shall never want a man to sit upon the throne of the house of Israel". This is either referring to Christ or David himself.
And look how the priests and Levites offer offerings continuously. That has not happened. This again demonstrates how OC practices will be in force around Jerusalem in the Millennium.
Jer 33:14
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Behold, the days come, saith the LORD, that I will perform that good thing which I have promised unto the house of Israel and to the house of Judah.
God has not yet fulfilled showing His divine blessing of Israel and Judah. Today, since 70 AD, till the end of the "time of the Gentiles" this blessing is on "pause". It is clear that the Jews are not blessed today. Note the holocaust and the state of Israel today. But they are in for it - in for divine blessing soon.
In summary, Jesus DOES NOT sit upon the throne of David yet.
When He does, He will rule. Christ sits on, not even His own throne, but on the throne of the Father, at His right hand, until the Father makes His enemies, His footstool. Future.