It is not like there is an Interstate highway across to Puerto Rico from the mainland, like there is between the rest the United States and both Texas and Florida. Everything in Puerto Rico comes in by A) air; or B) cargo ship. Docking facilities and open airstrips are a vital necessity in that instance, there can be no shortcuts.
The first thing absolutely essential MUST be done, is to make sure ships can dock and aircraft can land. And I believe almost all the early efforts were directed at opening this vital link. After that, it was a matter of motivating those in charge of the local distribution channels to make timely deliveries to the best of their ability.
If that means there an awful lot of chainsaws going, and local law enforcement directing and aiding the flow of traffic into and out of the worst zones, and the other cleanup people are on the job, giving due diligence to the task at hand, that is how to climb out of the hole, one advance at a time.
You stated: “It is not like there is an Interstate highway across to Puerto Rico from the mainland....”
I ask you “WHY there isn’t?” Let’s face it, it is only because the Republicans under Trump and Bush did not want it built and their obstructionist and anti-Latino biases toward Puerto Ricans that the kept the Clinton and Obama administration’s efforts to build it!!
(the above said with my SARCASM throttle wide open.)