Well I guess you can; https://search.brave.com/search?q=hawaii+drill+water+well
I know rainwater collection is used widely so maybe wells are cost prohibitive. I didn’t realize there were fresh water aquifers under the middle of the ocean.
I didn't either!
I suppose the type of soil the island is made from would make a big difference.
I saw a travelog about Bermuda once. It showed a quite extensive rooftop system that supplies water to everything!