Hand made cave? Ooooook......
But I like to make sure my family had shelter what ever the emergency.
I also hate to brust your ‘Mad Max’ fantasy but not every emergency requires the taking up of arms.
I have never anticipated anything at all resembling “Mad Max”
I anticipate action in the continental United States more resembling what I experienced during the ‘91 war.
Small arms isn’t going to do well in an artillery and air power duel, and idiots running around armed and out of uniform are going to be assumed to be the enemy by foreward observers of all sides. Godhelp anyone who engages the uniformed forces and then thinks a building is going to protect them.