Most jobs don't demand a steady stream of life and death decisions on 12+ hour shifts with terrible pay. The closest would be the medical industry, and typically screwups are disciplined but rarely result in firing.
Most police jobs don't demand that either. I know retied cops who never had to make a life or death decision in their job. (except first-aid situations which happen often but are different than this discussion)
It is useful for police to have a gun (but not required!), and they should know how to use it. However that doesn't mean they should use one off the practice range.
The most stressful decision your median NYPD officer faces every day is whether to double-park in the bike lane or in front of a fire hydrant while getting their Starbucks. An MTA bus driver makes 1000x more life-or-death decisions per shift.
