If everyone drove 1mph do you believe there would be as many car accidents from slipping? Nope. This type of event occurs because of human misjudgment.
Yes, and the world would also be a safer place if people went 0 miles per hour and never left their houses, but both situations are pointlessly unrealistic.
We won't see a major population of self driving cars for decades. There are perhaps a dozen live models. We have millions of human driven cars now. This is the problem we solve for, not the ideal future fantasy.
I think you missed the point. I didn't give the 1mph example to imply that it should be the way it is. I used it to point that you are incorrect in saying "or maybe they were not." Accidents, mishaps, misjudgements, say what you will, but they are all just human error, not "acts of god." So you are incorrect to say they were anything but that, no matter how much you wish they were.
We also solve for the future all the time, constantly, every day. We build solar powered devices to stop global warming and pollution. Every day we work towards a "future fantasy." It is like saying we don't need roads because we have these horses we have been riding. Why build rubber wheels when our wood carriages work just fine. Why build a smaller computer when this massive datacenter works just fine.