On the other hand, some things are powerful, but not particularly difficult. On a purely physical level, this includes operating heavy machinery, or piloting drones. (I'm sure it's not easy, but the power output is immense).

I think powerful but not difficult things will be hard to find (think about efficient markets).

Let's take piloting drones. The "power output" of a Hellfire missile is pretty impressive. But do you, the pilot of a drone, have that power? Not really. You just do what your commanding officer tells you to do -- it's not up to you to pick the target. And how does he decide who to kill? He gets told, too. Follow the chain and you'll end up with the kill list that is (supposed to be) personally approved by the President of the United States. That dude does have the power. But the difficulty of getting into his position is... considerable :-/

It's a complex issue. Does buying a gun -- which is easy to do -- make you powerful? In some way, yes. In some way, no.