Land anywhere useful is also extraordinarily expensive and developing industry is commonly blocked on the thinnest of reasoning. Hawaiians even sabotaged the interisland ferries on some trumped up environmental concerns (they complained a couple people loaded sands or rocks) seemingly being scared shitless of their own people from other islands having cheap access (the tourists just fly so it has nothing to do with overtourism concerns). You can hardly develop any infrastructure that's not tourism or residential, and residential is also usually tough outside the big island.

Also the various cultures on the islands have a tenuous peace as a legacy of cane plantation owners purposefully segregating and pitting the natives, Chinese, Filipinos, and whites against each other. This lives on in everyone sabotaging the development of any other part of the islands and things like 'Kill Haole Day' in the very welcoming public schools.

As a result of this everything is even more expensive than just the shipping and isolation issues.