>>599230
They're pretty great if you want to sponge away blood so you can see inside, but gunshot wounds are more complicated than just plugging the hole. Covering it up just hides the fact that your spleen is exploded, or you have a venous bleed, or some vital organ is fucked up.
If you're in the middle of a battlefield and there's no medic around, they'll pack you full of garbage just as makework, to have something to do before you die horribly. Any trained medic is going to get out a couple of clips, find the bleed, clip it, and stabilize you with a pack of saline. You can wait that way for days.
Nothing beats good training.