Game: tat. Tat. Tat. Tat tat tat tat tat tat tat
Real life: brrrrrrrrt
There isn’t a video game minigun in existence that will bankrupt you in seconds either, you just gotta suspend your disbelief and enjoy the fantasy
Except for maybe bloodborne. The most fantastical minigun but you become bankrupt in multiple lifetimes attempting to acquire it

I guess that if I was trying to make realistic game, I would give the player multiple lives. Each mission, there is a large number of friendly troops trying to advance through each area. Whenever the player dies, they swap into one of the surviving soldiers. The game is over if the troops run dry. This allows us to have each and every weapon on the field be fully effective for both sides.
There are a lot of difficulties with this, since traditional game design doesn’t account for a massive number of characters. It would probably be best to make a mod for Arma III and playtest the concept with D-Day and other operations.
It would be kinda like the isometric Army Men games or Cannon Fodder, but from a FPS perspective.