Neither the author, nor anybody that I can see here, is saying that the author didn't make any mistakes.
But what you are saying is that marginal effort to prevent mistakes is not worthwhile.
Cars, to take your example, would not be as safe as they are today if they followed the principles you've shown in this post and the grandparent. And yes, even when driving drunk, which is illegal, is safer too - stay in lane, adaptive cruise control, automatic braking, etc. have all incrementally made even extremely ill-advised behaviours safer.
But what you are saying is that marginal effort to prevent mistakes is not worthwhile.
Cars, to take your example, would not be as safe as they are today if they followed the principles you've shown in this post and the grandparent. And yes, even when driving drunk, which is illegal, is safer too - stay in lane, adaptive cruise control, automatic braking, etc. have all incrementally made even extremely ill-advised behaviours safer.