I understand statistics but that doesn't make the distinction trivial. Nobody is suggesting (I think) that we should ignore any problems these vehicles represent. That we even need to "argue" this is kind of crazy: lots of people die, get in car minor/moderate/severe accidents that cause injuries, etc. and there is no computer at fault. Getting into a car accident that isn't your fault is basically random.

So why pretend like it's not important to cite how many people die today? We write laws and rules for how to operate vehicles that can be observed and operated by a computer. It's very likely that at a certain point those computers will exceed our aggregate ability to prevent deaths.

There are likely also wins we could get from the design of vehicles by not having to accommodate a human driver. Take for example the window that a person can be ejected from the vehicle through or debris can easily penetrate.