What do you mean “fast enough”? You can’t predict something that doesn’t exist i.e. not visible to the sensors. A Waymo wouldn’t move at all if it assumed people would always jump out of nowhere.
Even if you detect “fast enough”, there are physical limits for braking and coming to a stop.
You’re being vague and hand-wavy yet again.
Do you stop at every double parked vehicle when you’re driving? A Waymo would never move if it always predicted pedestrians would jump in front of it out of nowhere or the car next it would swerve at 65 mph. It’s physically impossible to stop in time for many accidents, unless you’re already stopped.
You are predicting stuff that your sensors don’t see all the time my friend