More than anything Cooper it's battery technology has improved immensely... I bought a 3spd Dewalt cordless drill, maybe 2002, always stored in the warmth of the house, not used too often & both batteries couldn't hold a charge a couple yrs later. That 14v Dewalt cost more than the two Milwaukes together.
My neighbor has Bosch cordless gear, couple yrs ago framed & sheeted in a 26x26 garage in one day with cordless skill saw, 3 packs worth... impressive!