Strangely soft plastic lures have never really caught on in New Zealand. I have had quite a bit of experience on soft plastic lures and I can tell you they work very well on a wide variety of species. You can get incredibly life-like imitation soft plastic fish nowadays that swim and feel just like the real thing. They work great for both trout and saltwater species.
Perhaps one of the downsides of soft plastics is that they don’t last long on some species. Kahawai in particular chew them up very quickly. You can patch them by heating with a lighter and pressing the bits back together if you still have them.
You can get large bags of soft plastic worms, shrimps and such like. These work out at just a few cents each so who cares if they get munched-up! For jigging or casting they work as well as fresh bait..