Why the Restoration of Israel Had To Wait Til The Great Commission Was Fulfilled

After Christ's Resurrection the desciples asked Him,
"Lord, will you now restore the kingdom to Israel??"(Acts 1. 6).
The second part of His answer was,"You must [first] be My witnesses to all nations"(Acts 1.8).
In other words the Great Commission must be completed first(Matthew 28.18).

Why is that?? How does that make good sense??
Well, Christ said"The first shall be last, and the last will be first"(mat 20.16;Mk 10.31; Luke 13.30).
Israel had been "first," in the sense of being the "chosen nation."
And the Gentile nations had collectively been "last." Behind Israel.
But when the Jewish leaders rejected the true Messiah and followed Bar Kochba,
 a false messiah that Christ predicted, with the masses blindly following their "blind guides,"
The Jews went to the back of the line, becoming "last," instead of "first."
Logically, this means they should be (about) the last nation to be reached by the Gospel and the evangelists.

So it is only logical that if Israel is in the category of  the "last," the Great Commission should be (at least in some minimal sense) completed "first."
Before Israel comes back into existence as a sovereign nation.