Yeah, not funny because Presidents can, and often do, kill people with drone strikes. It would have been funny if he pointed the joke at a hurricane or shook his fist at God while saying it.

If he wanted to make a dad joke he could have said he had a shotgun or would box them or challenge them to a duel or something. That implication of superiority with balance can be funny, like Mike Tyson joking that he was going to kick your ass if dated his kids. Enough of a flex, but the balance is maintained because if you train hard enough or knew enough kung fu maybe you could take him.

Joking about firing people and calling a drone strike on them are not funny if you can actually do it but they can't do it back to you.