Anti aircraft weapons work just fine in taking down drones. Other military aircraft generally have little to no problem in taking out drones. Also, while it’s pretty damn hard to take out a low flying military grade aircraft with small arms or assault weapons, it’s not as hard to take out a low flying drone given that they’re also more susceptible to damage from those sorts of weapons. The big advantages drones have, are smaller size making them harder to spot, stealth technology benefits them further against radar and – in some cases – they’re level of maneuverability is superior to other aircraft. And in some cases, the signal from the controller can be interrupted rendering the drone fairly harmless, like in the case two(?) years ago in Iran I believe it was.