It is a good question. I have only been hit from behind once and I’ve been driving 46 years averaging about 30K miles per year (I did the math, about 1.5 million miles).
I really pay attention to having a “cushion” in front of me, or a space between me and the vehicle in front of me. I use the 2 second rule, and feel more comfortable with a 3 second space. If you don’t know the rule it means you mark a spot on the road that the car in front of you just passed and count to 2 or 3 seconds; “one one thousand, two one thousand, three one thousand” and if your car rolls over the spot in the road before you finish 3 one thousand you are too close. In snow and ice you give more distance. When a jerk is sitting on my rear bumper at 70 mph I am very uncomfortable and I’ll make sure I have my cushion in front so I don’t have to stop quickly. If there is no cushion in heavy traffic, I’ll slow down just a bit to create some more room in front. Without my cushion if brakes lights come on in front of me I’d have to hit my brakes and that can make the guy brake hard and a bad chain reaction can occur. The cushion is the key.