Submachineguns, what are they good for?

Now that I've decided upon the main rifle in my new upcoming Morrow Project campaign (featuring new and improve alien mayhem), the next item on the list was to be Submachineguns. The original game included a number of different models, and I turned my attention towards them with fond memories, but then reality dashed those rather quickly.

What would I use these for?

Things like the MP5 are five and half to nearly 7 lb weapons. Meanwhile the HK416 carbine with a 10" barrel is 6.7 lbs. That's not much of a weight saving, and the recoil of the HK416 isn't meaningfully worse for the typical character- so that's not a significant advantage either.

And the 9mm round the MP5 fires is worthless compared to even the worse of assault rifles, let alone the 6.8 SPC round that I settled on. Why would I want a less powerful, much shorter range weapon that basically weighs the same?

There are smaller SMGs to be sure, but those bring into play isssues of control as the lack of weight and size reduces one's ability to keep the weapon on target when set to autofire. Sort of counter-productive isn't it?

Some are small enough to use as concealed carry (i.e. like the Secret Service has been known to to do). That's useful enough even with a bit of control problem (countered by using the weapon at very close ranges), but the Project isn't the Secret Service and has little need for this advantage.

The one area when they do show some promise is that they can be fitted more effectively with a suppressor to muffle the sound and flash of a shot. The new H&K 2000 can even be set to vent gases to reduce standard ammo to subsonic velocities to take advantage of that. Rather cool- and rather specialized. Not something the typical team member would ever use although I could see them be used by specialists here and there.

They do also have the advantage of not blowing through walls and killing people you don't want to kill. But there's AR ammo that gives you that ability if needed.

So, nope. No standard issue SMG for the Project although they may appear in specialist teams. Oddly enough, the US Military and I agree on this point. They have dropped them as standard issue as well, although they remain in rare use because of their suppression advantages.

What about PDWs? These are what SMGs are developing into. Things like the FN P90. Meant to overcome armor while being small and more easily carried... well, meant to be anyway. They are at least better against armor than previous SMGs were.

But the problems here remains much the same. The P90 is 5.5 lbs unloaded- only a 1 lb saving over the HK416 Carbine. Just not enough of a difference to make up for the disadvantages IMO. The MP7 is another lb lighter and much more compact and might almost work except...

...that the International Wound Ballistics Association current viewpoint is that they lack the stopping power of normal SMGs (let along rifles) against unarmored targets.

Nope, I'll have to pass on them too. Just not enough to be gained for what is lost.

SMGs were wonderful weapons for WII and preceding. But that was then and this is now. Their day is past outside a very narrow role. Time to move on to other weapons.