Layers are critical! Lots of people "have a gun" or "have a security system" or "have a dog". It is best to have all of the above and A PLAN. Even then there are no guarantees. A determined criminal, or criminals, with enough time and knowledge, can defeat any and all security measures.
My defenses include all of the above as well as distance from the road and everyone in the house is trained in the use of firearms. Criminals would have to be pretty desperate to try to break into my house in town but I am under no illusions that someone won't try. We have a revolving door of cars and trucks in addition to the ones we own that are constantly moving around the property so even if we aren't home there will be at least a couple of vehicles parked out front. A criminal could sneak in and steal things from my out buildings but making it into the house past the lights, security system BIG dog and reinforced deadbolts will be a challenge.
I can replace things.