Weird, I actually fly helicopters for a living, and I can tell you the difference this would make.

Helicopters can't land in rough ass terrain, so they're required to use a basket hoist (before you say they don't, they do it all the fuckin time where I live, so idk why people think it never gets done).

If the patient is basically already ready to go once the helicopter arrives (which takes time), they can just lower a basket, the ground guy can throw em in, they go up, and the helicopter is off.

Now a dude wearing a jetpack might seem completely unnecessary in most situations, because it is, but if you have a critically injured pt on the ground, the 5 or 10 minutes that patient doesn't have to wait to get on the way to a hospital could be the difference between them living or dying.

Minutes make a huge difference when you have less than an hour to live