Was trying not to be too far into the principles, but
Magnetic is all over it. The basic principle of security is that nothing is perfect. You are trading off (cost, convenience, etc) for time, and not relying on any one thing but a layered approach.
Fire security is an easier one for many to envision, but the same applies to people trying to pick, cut, or pry through doors. If you read little signs sometimes you will see a "30 Minute" wall, for example. This means it can handle the expected level of fire for 30 minutes with no firefighting efforts. You store gasoline in the building so the fire is hotter? Now it's an 8 minute wall. If you penetrate the wall — either damage from a blast, from items collapsing, or just workers drilling holes to install stuff, which is why the sign is there — then all bets are off.
Time.
Note that commercial buildings all have sprinklers, and fire extinguishers, and well-lighted exits, and regular fire inspections.
Layers.
For me, in a niceish suburb with typical fire response under 2 minutes, networked smoke detectors, nosy neighbors, house-sitters when away from town, etc. etc. I am not essentially at all concerned about fire safety, so don't need additional fireproofing, only have a few documents and backup drives in fire safes. For nefarious/deliberate threats: the same plus I have the highest security stuff behind a second door (more time) and I am also adding in motion sensing (sends notice to me) cameras, so anyone in the safe room when I am not there: bad thing and I call the local cops to come deal with it (reduced time).
If I was half an hour outside town like my one friend, I'd take a very different approach. And he is as he builds his new house on the opposite corner of his property. Doing a gun room, but sticking out from the house, not near the garage etc (cars are full of gasoline), and is fire insulated on all sides. Because instant fire detection could still be 20 minutes for the FD to get there with distance and twisty gravel roads. It could be an hour when you count weather, detection, and communications (bad mobile coverage so poor backup) time. Or what if you are in a wildfire area, and the FD is busy with everything being on fire. How far off are the neighbors: can they see smoke, or hear bad guys grinding through locks?