This is my opinion lacking research
It actually involves the size of the island and the location.
If it were a small island you might lack critical things you need for survival. ( con )
But you get to enjoy the beautiful scenery of the island and get to experience what its like to live on an island ( PRO )
Dangerous animals could inhabit the island putting your life in danger ( CON )
When living on the island you wont have to inhale the mostly polluted air found in cities but this more different if you're in Hawaii ( PRO )
- last one - Some islands have volcanos and constant earthquakes which could also put your life in danger ( CONS )
hope this helped :)