The thing you're missing is that the decision isn't actually made by a machine. It's made by a person much much higher up across a much broader effective surface area.
That is, historically to wage war you had to ultimately convince/coerce millions of people to wage that war for you -- continuously for years -- along with millions more to support the effort politically and economically. In the highly automated world, you literally only need a lot of money (which also tends to concentrate outside of any semblance of democratic control).
Yeah a single rich person might soon have the ability to, without coercing a soldier, decide who gets to die. He might just need to coerce someone to deliver the drones and put them on an (automated) truck.
The smart-ass answer is 'a single person already does, and he doesn't need to be rich, just able to build a time-bomb and send a package'. The Unabomber approach has its limits of course, including being hard to reach those who do not open their own mail.
The amount of autonomy and decision complexity matters a lot. Autonomously making its way into a known area, recognizing the target and self-correcting to it is basically how every modern cruise missile works.
So the interesting question is to what extent the Iranian derived Hezbollah "garage rockets" (very poor guidance, CEP is basically "somewhere in Israel", but extremely cheap and require only smugglable parts) can be combined by some power with Ukrainian style precision guidance.
Well, this week proves that range and velocity limitation can be overcome if you ship them near to their destination in small boxes ahead of time. This wasn't really an option with cruise missiles.
That is, historically to wage war you had to ultimately convince/coerce millions of people to wage that war for you -- continuously for years -- along with millions more to support the effort politically and economically. In the highly automated world, you literally only need a lot of money (which also tends to concentrate outside of any semblance of democratic control).