There’s literally no good reason why anyone would ever want to actually use a handheld minigun.
First things first…it’s heavy. Because it’s heavy, you also won’t be shouldering it anytime soon, and because you’re not shouldering it, you also can’t aim down sights, and consequently you won’t be getting any accuracy with it.
Second, in this case its rate of fire actually works against it in this scenario. There’s a reason why most machine guns usually are around 500-800 rpm in terms of firerate, with even the fastest firing machine guns at only around 1000 or so, and that’s ammunition. When a minigun is used in a mounted role this is less of a problem because you can store more ammunition, but even so ammo is still consumed extremely quickly.
So, in summary, you have a extremely heavy gun that can run out of ammo really quickly that you also can’t be accurate with, with the only upside being that it’s…cool, I guess?
There should be “gatling guns” for helicopters and jets(let’s hope we have jets in II), miniguns for fire support and killing large amounts of zombies, and the microgun as a more tactical, close combat version of the minigun.