1. It's a function of cost. None of these things are cheap. 2. It might not be possible. Helicopters will need a somewhat direct line of sight to the container

1. It's a function of cost. None of these things are cheap. 2. It might not be possible. Helicopters will need a somewhat direct line of sight to the container (which might be tucked in a cave), boats probably won't reach (too close to the rocks#, submarines... Lol. The only viable approach is probably by land, which means months of construction work to bulldoze whatever obstacles there are... Which brings us back to point 1, cost