‘And Isaac his father answered and said to him, “Behold, from the fatness of the earth will be your dwelling, and from the dew of heaven from above. And by your sword you will live, and you will serve your brother. And it will happen, when you will break loose, that you will shake his yoke from off your neck.” '
Isaac grants him one favour. Independence. He will release him from his debt of servitude to Jacob.
“From the fatness of the earth will be your dwelling, and from the dew of heaven from above.” ‘From' here probably means ‘away from'. The fatness of the earth and the dew of heaven is to be given by God to Jacob (Genesis 27:28). But Esau is released from enjoying it. He may go away from his brother, away from God's provision. The land he will go to will not enjoy the same dewfall, and will not be as productive.
“And by your sword you will live and you will serve your brother.” His future will be in warfare and booty. He will be a raider at the head of warriors. ‘You will serve your brother.' This may be partly ironic meaning try to give him his deserts. But in the end it is prophetic and will be fulfilled when Edom becomes subject to Israel (2 Samuel 8:14; Obadiah 1:18-20).
“And it will be that when you will break loose, that you will shake his yoke from your neck.” The submission will not be permanent and in the end Edom will be free of Israel's yoke.
Esau does indeed leave home in accordance with the blessing and establishes himself in the mountainous country of Seir where the dew is scarcer and the land not so productive. But he gathers a band of warriors (Genesis 32:6; Genesis 33:1), builds up his own tribe, becomes wealthy in possessions (Genesis 33:9) and is free to do whatever he wants.
He was a free spirit and he would never have been satisfied leading the family tribe and being beholden to the inhabitants of Canaan. The family tribe of Abraham might well have been turned into a band of brigands. So in fact he found a future which satisfied him and this helps to account for his willingness to forgive Jacob and treat him as a beloved brother (33:4). It also explains why God, Who foresaw the situation from his birth, allowed what He did.
But that is in the future. For the present things begin to look ugly.