I think you need to compare it to the existing alternatives when boarding which are essentially a boat + ladder (fixed or grapple style) or a very large helicopter hovering above a static limited location (e.g a wide open space away from wires). Once people starting going down the rope, the helo is pretty much committed (albeit with covering fire most likely). Whatever happens, usually that process only then gets you on one place, e.g one level. Smarter defenders often make that harder for people assaulting - locating sentries, using barbed wire to block those places etc. You then have to fight, often through openish ground until you get to the first breaching points on that same level. Everyone is usually coming from the one location, for example where the ladder or helo rope is and doing it one by one. So it might take 30-60 seconds at least to get everyone onto the ship.

It would be much quicker to board and harder to defend if an assault team could land basically anywhere on the ship simultaneously. All of a sudden you have people assaulting from front, rear, sides, top and then downwards etc etc. You are suddenly trying to defend from 10 different assaulting positions. Plus the noise and signature of the jet packs will probably be lower than that of a helicopter, so a chance for more surprise. Anywhere with a small enough gap for the jet pack to land.

I assume also in future they will make the transition to fighting a lot faster, such as some kind of quick release mechanism to drop the jetpack stuff off you and get into the fight.

Also another side benefit is that you can use your jetpack to get back off the ship. That might not be the case if it's too tricky for the helo or assault boat to recover you.