Bullets are loud and require you to transport a gun into the area and find a spot where you can snipe at your target, both of which could be very difficult in,

Bullets are loud and require you to transport a gun into the area and find a spot where you can snipe at your target, both of which could be very difficult in, for instance, an urban environment. You probably would get caught. The poison warp bubble is much cooler and stealthier. And as someone else mentioned, you aren't restricted by the lightcone.