They didn't. They would recycle materials and make new buildings out of old ones or change the purpose of a building to a new one. They would also heavily use wood in building houses and things like that because it was available and was not that difficult to manage unlike stone.
The answer is "social contract theory".
It is the willful understanding among people by which, as per any of different speculations, as of Hobbes, Locke, or Rousseau, sorted out society is carried into being and contributed with the privilege to anchor shared security and welfare or to direct the relations among its individuals.
As soon as Israel had sovereignty in 1948 weaponized problems started
I’m not sure but I think it’s the second one