unless you have supportive research in human-feline relations, cat population epidemiology and comparative global felis catus sociology buttressing those anti-american presumptions, my cats will continue enjoying their happy indoor lives.
He's an adult (cat) and can make his own decisions.
I won't let my (small) fear of his death imeped his (great) desire to go outside.
Update: he lived a long-for-a-cat happy life and passed peacefully several years ago.
however your experience doesn't generalize, particularly your assessment of the risks and benefits.
i watched a neighbor's cat get hit by a car and then die in my hands. the mortality rate for cats in my neighborhood is probably north of 20% per year (huge). it would be irresponsible to expose my cats to such risk when they're quite content already. mortality would have to be less than 1% (small) for me to reconsider.