An old lady at the hospital I used to work at was killed by a bike rider crashing into her at a high rate of speed. She hit her head on the pavement & fell unconscious - person on the bike bailed, when she was found after a few minutes it was too late.
It is far easier to protect pedestrians from 4-wheeled vehicles with simple measures such as concrete bollards and fences, but a 2-wheeled vehicle can go basically anywhere a pedestrian can, and now with EVs they can do it way faster without much effort.