The roads would have been a mess right after the Snap. Just think: you're driving down the road, stuck in traffic cuz everyone needs to get home while the aliens attack, when half the drivers are suddenly gone. Cars are going out of control at 55mph at least on the freeways/highways. Doctors disappearing mid operation. Ovens and candles still on then the owners get snapped, starting fires. Single mothers who get snapped but their baby/small kids don't. The snap would have been worse than 50% fatal.