I'm sure the terrorists will continue, giving Israel the reasons they need. But they are a bunch of small groups with no cohesion, and minimal funding. Israel is a nation state with Western backing.Nothng you said renders my idea meritless. The option is to have a bumpy road to a possible peace or a forever war. All you have is "lets do nothing because its too hard" Your scenario is maybe one outcome. Another outcome is that these refugees trickle out including Hamas members, that will relocate and continue to strike Israel and Israeli interests from multiple directions. In any case, many Isralis are leaving as they see years of war ahead. So the Israeli economy has been ruined.
And no the economy of Israel is not ruined. It was far worse decades ago at its inception and still survived things. Now it has more money, and more foreign aid, as well as rich patrons in the west to help with loans and grants.
And once the Saudis come back in to a peace deal its over.