To counter balance your point : the original Volvo emergency braking system in the car saw the crash and wanted to brake 1,3 seconds before it happened.

So Volvo engineers didn't think at all like you do / say. Their system was 0,1 second faster than Uber at detecting it, 1,1 seconds faster if you factor in Uber active suppression, and it would have braked 2,1 seconds sooner than the Uber did.

Why didn't it? Because Uber deactivated it's braking ability.