Because this program includes more low rep, heavy strength work than a typical bodybuilding program, you will simply get much stronger in general. Once you apply that new found strength to the typical “bodybuilding movements” in moderate to high rep ranges, the potential for overload will be so much greater and plateaus can be completely busted.
Powerbuilding isn’t only valuable for bodybuilders, though. It also has merit for powerlifters. Remember, all else equal, a bigger muscle IS a stronger muscle. So, if your strength progress has slowed down, a powerbuilding approach will provide the muscle growth you need to make sure your numbers keep moving up.