A helo (whether manned a not) has advantages due to its ability to move at low speed or hover. Even a relatively slow propeller-moved plane isn't that handy as a helo.
No question. The problem is that helos are limited in maximum speed and altitude and they have a very recognizable rotor disc to contend with. The Russians have developed (and no doubt shared) and tank-fired guided round that seeks helicopters using a millimeter wave radar seeker that "sees" the rotor and targets it.