Does your risk assessment methodology also account for near misses? Agency? Morality? Source of risk? Costs of mitigation? Benefits? Something like actuary tables?

Mitigation of bike and pedestrian deaths is cheap. Just reform land use, advantage people over vehicles. Oops, now you're into culture and values.

Mitigation of cancer deaths is very expensive. Though we didn't invent cancer, we feel the moral imperative to "cure" it. And yet, while we're mitigating it, we're also making it worse. Cross purposes. What's your balance sheet for this conundrum?

Drugs kill lots of people. We own that one, right? How's the War on Drugs working out?

In conclusion, I wish I could wave away these dilemmas with a cute nominator and denominator. But I can barely reason about them before my head explodes. So I'm not buying what you're selling. Life's a bit more complicated, a bit more empirical, a bit less rational, than your tidy equations.