[kjksf]

> statistically significantly reduce

And how does one prove something is true "statistically"?

By doing it many times. So many times that you can be statistically confident of the result.

Statistically, there is ~1.4 deaths per 100 MILLION miles driven.

To prove, statistically, that software is as good, it would have to drive at least 1 billion miles. And yes, it would kill 14 people in the process (or more, if it's worse than humans; or less, if its better).

Tesla is already doing what you say car companies should be doing i.e. statistically testing the software

Except you don't like it and think there's a magic fairy test that will show something "statistically" without driving statistically significant number of miles.