If you save a child from drowning you don't get a 'a kill coupon' you can retrieve next time you are accused of murder.
The ratio isn't 1:1 or even 1:10, but there is a line somewhere where X deaths <caused by new tech> is acceptable because of the X^Y lives saved <by new tech>.
See also: Most modes of transport, most medicines and surgical procedures.
Nothing good comes from trying to treat them as the same.