Nat6999
Considering all Ukraine males have to do a year in the military I would think most of them can shoot. They are being given AK47 rifles which I have read are the simplest rifles to use. I applaud anyone who has stayed to fight & defend the homeland
AKs aren't the simplest. They are the best in wet, sandy, crappy, muddy, dirty places. They don't fail. They do kick a bit so you'll feel it in your shoulder and aren't the most accurate but you don't need that
They are by far the most soldier-proof - easy to strip and clean, and less likely to jam, withstands all sorts of harsh conditions, big, obvious controls so pretty intuitive to use
They're no more simple or complex than any other assault rifle. But they're cheap,and widespread. If you're after accuracy, you'd do better with other assault rifles (such as the AR15), but if what you're after is to hit a man-sized target at say 300 yards, it'll do the job.
They're not WMD of course - they're individual weapons, but in the sense of the cumulative numbers of deaths people have used them for, it must be one of the highest. It's a sobering thought They are cheap, widely available, keep going for ages even with minimal maintenance, and are so straightforward to use that you don't need to be clever, to have any education, or even to be adult to use one well.