Because that is science fiction.
Not any more. You need whole headsets and stuff for the moment, but with the 5g you can transmit enough information to just a chip in someone's head to pull it off. Of course, the goal is simply waves.
Also, that's just the aim, there are current applications. From a distance of several miles, you can transmit neurological signals that will cause depression and ultimately demoralize an entire target group instantaneously. Essentially it triggers your brain to withhold dopamine excessively and release other chemicals that will quite simply make you sad. Since morale wins battles (not so much since ac-130 gunships, but vs. someone other than America still) massive military advantage from that.
Under development, and in need of funding isn't the same as science fiction. More than 10 years ago they developed a headset that allows researchers to control you. You press forward, and you simultaneously feel the greatest physical and emotional pain to stay still, while even the thought of moving forward is rewarded with massive dopamine. It isn't perfect, I can resist it with some effort and pretty easily when lying down, the pain tastes good, but all the nerds couldn't help themselves. That you can put in a chip now. Once as that can be transmitted, a big army is a big liability, unless you're in the new weapons race too.
