Ever heard of the Kingdom of Israel? David? Solomon?
They descendants of Abraham saw the promise fulfilled. Those descendants chose to stop following God. God gave reprieve after reprieve. He finally let them go, preserving a remnant through Babylonian captivity to fulfill the promise of the Messiah.
The Messiah did not come to restore the physical Kingdom. Jesus told them that His kingdom was not of this world.
We could debate whether the nation of Israel ever possessed the land boundaries stipulated in Genesis 15. But that is not the most fruitful place to debate. You see, there is a bigger problem if you hold that the kingdoms mentioned fulfilled the land promises in the Abrahamic covenant.
Gen. 13:15 ... for all the land which you see, I will give it to you and to your descendants forever.
The Lord God said that Abraham HIMSELF ... as well as his descendants would possess the land. Recall that Joshua went into the promised land some 400+ years after Abraham was dead.
If the Lord promised the land to Abraham himself, and he died before any of the land was possessed, then the fulfillment of this promise is still future. Then on top of that there is the 'forever' aspect of the promise. The Jews do not currently possess this land ... therefore, what they had before, whether you believe it was all of it or not, they did not possess forever ... therefore the promise is yet to be fulfilled.