Little boys do not fully understand the matter of field communication. They have yet to learn of such things as calling in artillery or calling for medevac. So it is that in the set of fighting soldiers, the radio guy is usually out there with the binoculars guy and minesweeper.
Man-carried radios first became practical in World War II. They have been a mainstay of combat units ever since then. The most common types are pack radios, though smaller types have been employed. The "walkie talkie" was a smaller hand-held radio in its day. Actually, it was the size of a shoebox. Smaller squad radios appeared in the Vietnam era. Neither they nor the walkie talkies had the range and power of a pack radio.
In real life, the radio guy is a necessity. The radio links a small unit with the larger. It gives access to all kinds of support. Radio can send a warning of unexpected conditions or call for additional firepower. Communication is essential.
Little boys preferred the shooting guy and the bazooka men and other weapon handlers. For playtime, the radio guy became a crewman on a howitser or some other back-of-the-lines work. Then again, who needs communication when your entire side of the battle is all in your own head?
The radio man is an essential part of every platoon. He is also a prime target for the enemy. In our day ,we were taught that if confronting the Russians, to get the radio man. Unlike us, who had all been familiarized with radio communication, only a designated radio operator was trained to handle the Russian radio. I don’t know if that has changed.