Let's assume you are correct and aid ships can reach Taiwan.
Let's assume that these ships are even able to unload.
OK. How do you bring the aid from the east side to the west side where 90% of the population is?
Each person drinks 2 liters of water a day. Once water treatment plants - which are big, stationary and open structures - are destroyed, that means Taiwan needs ~40 million liters of water per day. That is only to drink - no toilet, no washing, nothing but drinking.
A typical tanker truck holds 40k liters of liquid.
You need 1000 tanker trucks going back and forth between the east and west coast
every single day just to keep Taiwanese population alive with water. No food, no ammo, no medicine, just water.
Tanker trucks has fuel efficiency of 40 liters per 100 km.
Taiwan is about 100 km across. You need 80 L of fuel every day per truck - 80k liters total -
every single day - just to keep water up.
You cannot lose even a single truck or people die of thirst.
There are 3 main highways from east to west, 1 of which is a narrow mountain road. Can they even fit 1000 trucks every day going back and forth? Have you ever seen even 10 tanker trucks in a row, let alone 1000?
You also need ships bringing in ~40 million liters of water every day, because water treatment plants get bombed. 40 million liters of water is 40k tons. That's an oil tanker worth of water,
every day. Lose 1 and it's over.