I doubt that "millions" of children have been killed by even something so common as auto accidents in the last 50 years! If you ballpark it at 50K deaths (all ages) annually, and multiply that by 50, you don't get 3 million ...... unless you do some serious statistical gymnastics (such as claiming 25 year olds are children) you don't get "millions of children" killed in auto accidents.
Grandstanding for the Low Information Voters, pure and simple.
Sadly, that's all it takes.
TheGolden Rule of Tool Use: "If you don't know what you are doing, DON'T."