From the beginning of their entry into the land of Canaan the conquest of the Canaanites was a work in progress.
Under Joshua a fair proportion of the land was taken. The whole of the land was divided and allocated by lot to the 9 1/2 tribes (Joshua 15 – 19). The tribes were insufficient in number to occupy the whole of the land, so the occupation was intended to proceed as the nation grew in number.
Exodus 23:30 By little and little I will drive them out from before thee, until thou be increased, and inherit the land.
Deuteronomy 7:22 And the LORD thy God will put out those nations before thee by little and little: thou mayest not consume them at once, lest the beasts of the field increase upon thee.
Israel was warned of the national consequences of not driving out the Canaanites.
Numbers 33:55 But if ye will not drive out the inhabitants of the land from before you; then it shall come to pass, that those which ye let remain of them shall be pricks in your eyes, and thorns in your sides, and shall vex you in the land wherein ye dwell.
The tribes did not utterly destroy the inhabitants as the opportunity arose. They allowed them to remain in the land.
Judges 1:21 And the children of Benjamin did not drive out the Jebusites that inhabited Jerusalem; but the Jebusites dwell with the children of Benjamin in Jerusalem unto this day... 27 Neither did Manasseh drive out the inhabitants of Bethshean and her towns, nor Taanach and her towns, nor the inhabitants of Dor and her towns, nor the inhabitants of Ibleam and her towns, nor the inhabitants of Megiddo and her towns: but the Canaanites would dwell in that land. 28 And it came to pass, when Israel was strong, that they put the Canaanites to tribute, and did not utterly drive them out. 29 Neither did Ephraim drive out the Canaanites that dwelt in Gezer; but the Canaanites dwelt in Gezer among them. 30 Neither did Zebulun drive out the inhabitants of Kitron, nor the inhabitants of Nahalol; but the Canaanites dwelt among them, and became tributaries. 31 Neither did Asher drive out the inhabitants of Accho, nor the inhabitants of Zidon, nor of Ahlab, nor of Achzib, nor of Helbah, nor of Aphik, nor of Rehob: 32 But the Asherites dwelt among the Canaanites, the inhabitants of the land: for they did not drive them out. 33 Neither did Naphtali drive out the inhabitants of Bethshemesh, nor the inhabitants of Bethanath; but he dwelt among the Canaanites, the inhabitants of the land: nevertheless the inhabitants of Bethshemesh and of Bethanath became tributaries unto them. 34 And the Amorites forced the children of Dan into the mountain: for they would not suffer them to come down to the valley: 35 But the Amorites would dwell in mount Heres in Aijalon, and in Shaalbim: yet the hand of the house of Joseph prevailed, so that they became tributaries.
God remonstrated with them but the damage was done.
Judges 2:1 And an angel of the LORD came up from Gilgal to Bochim, and said, I made you to go up out of Egypt, and have brought you unto the land which I sware unto your fathers; and I said, I will never break my covenant with you. 2 And ye shall make no league with the inhabitants of this land; ye shall throw down their altars: but ye have not obeyed my voice: why have ye done this? 3 Wherefore I also said, I will not drive them out from before you; but they shall be as thorns in your sides, and their gods shall be a snare unto you.
Judges presents a picture of the nation continually turning to Canaanite idolatry.
The land promised was from the river of Egypt (Not the Nile but the Wadi el Arish – the border of Egypt) to the Euphrates:
Genesis 15:18 In the same day the LORD made a covenant with Abram, saying, Unto thy seed have I given this land, from the river of Egypt unto the great river, the river Euphrates:
When we get to the time of Solomon Israel had control over all the land promised to them, but the Canaanites were still resident. This was temporary, Solomon turned to idolatry.
1 Kings 4:21 And Solomon reigned over all kingdoms from the river (Euphrates) unto the land of the Philistines, and unto the border of Egypt: they brought presents, and served Solomon all the days of his life.
Israel were ensnared by idolatry and removed from the land by Nebuchadnezzar.
They will not possess the whole of the land promised until Christ returns.
Luke 1:32 He shall be great, and shall be called the Son of the Highest: and the Lord God shall give unto him the throne of his father David: 33 And he shall reign over the house of Jacob for ever; and of his kingdom there shall be no end.
At that time the land will be divided up among the tribes as described in Ezekiel 45 and 48.
I hope you have found this helpful.
God bless you,