You've said, "You suck at abstraction" to two people now who've explained very clearly what's wrong with your understanding of the study. If you can't be bothered to explain yourself nobody will know what you mean.

It's hard to see how "quality of life" can be balanced against enormous numbers of people killed, but it sounds like you can't name anything that kills more kids? Maybe because there is nothing? Maybe this is a huge problem and saying, "cars kill kids" is actually pretty valid?

Cars are terrible for quality of life unless you live rurally. Not only are they massively wasteful, their highways cut swathes through communities, they create noise pollution, they dominate our landscape and rob us of communal spaces, and they cause urban sprawl and force us into enormous and stessful commutes.

There is no part of our lives that is made better by cars. You can't just say "quality of life" and expect that to mean anything unless, again, you explain yourself. You don't seem interested in doing that though.