good durability against earthquakes Unreinforced masonry is pretty much the worst class of building materials in an earthquake. Hence it is largely prohibited

good durability against earthquakes Unreinforced masonry is pretty much the worst class of building materials in an earthquake. Hence it is largely prohibited by modern building codes for occupied structures and severely limited when allowed. Mud buildings aren't cake to modern construction's bread. The old city is made of mud because mud buildings are better than nothing (except in an earthquake) and better than nothing is better than nothing.