I don’t think the average human has enough mass to meaniningfully use a crumplezone. The trend of higher bumper heights causes more head an chest injuries than lower bumper heights. Higher bumper heights also increase the chances of being run over.
The average car is also much heavier these days and simple math means that car will have more force on impact at the same speed compared to a lighter car.
Cars don’t need to be going high speeds to be dangerous to pedestrians. Roads near pedestrians can be designed poorly allowing drivers to go significantly faster than the intended limits.