Most pedestrian crash tests are at low enough speed that there isn't visible energy absorption, plus most dummies aren't equivalent to most human scales. They tend to be modeled after a 6' adult male at around 200lbs.
The bigger issue with larger vehicles is their height around people current full size or even mid-size SUVs and trucks have gotten larger than their former variants. You're much more likely as a pedestrian to get run over than to be hit by a car and land on the hood or the windshield (which is by far the better position to be in during an accident). The crash bar behind the bumper on all cars have a thick layer of foam that contributes to the 'softness' of a bumper.
The bigger issue with larger vehicles is their height around people current full size or even mid-size SUVs and trucks have gotten larger than their former variants. You're much more likely as a pedestrian to get run over than to be hit by a car and land on the hood or the windshield (which is by far the better position to be in during an accident). The crash bar behind the bumper on all cars have a thick layer of foam that contributes to the 'softness' of a bumper.