I’d argue digital ads kill people just via indirect means. Think of all the “dangerous” ads - fast food, alcohol, weight loss and plastic surgery, unnecessary medications, even guns. All of those things kill people over different time horizons and circumstances. Would individual people have bought the stuff without ads? Maybe, maybe not, but on a statistical level I’d guess it would be significantly less. So arguably ads do kill people and probably more than Lockheed Martin’s weapons do each year.

Addressing just what you regard as a logical point, a great deal of expensive weapons technology (eg: nuclear weapons) serve as an unused deterrence, a good deal more acts to hold a line and can prevent the killing of people advancing to others.

The error is more akin to the assumption that, say, intelligence is similar to height and that one person is definitively smarter or not than another just as one may be definitively taller or not.

Weapons tech and advertising tech are apples and oranges, each with their own spectrum of pro's and cons.

isn't that like saying that rocket motors or inertial reference units don't kill people?