Why is it always about running to the sidewalk or the other lane? There's also the option to reduce speed as much as possible, aka break hard, that a computer can do a) earlier than a human would b) much harder than a human would. Yes, the people in the car might take a lot of negative Gs. But that's also an option. The car might still hit the kid, but the difference could be some broken bones, or with chance, bruises, vs. death.
> There's also the option to reduce speed as much as possible, aka break hard, that a computer can do a) earlier than a human would b) much harder than a human would.
a) A computer can initiate braking a small fraction of a second faster than a human, which is great but not such a huge difference in braking distance.
b) A computer cannot brake any harder than a human, certainly not "much harder". The max deceleration rate is traction-limited, which any remotely modern car (last ~25 years) can easily sustain with an untrained driver thanks to modern ABS.
(As a side hobby I instruct in car control and accident avoidance clinics. Blindly braking hard is not often the best answer.)