Disadvantages of living on an island include social and geographical isolation, a lack of employment and educational opportunities, transportation problems and small community challenges. These issues are minimized on large islands, such as Britain and Japan.
By nature, islands are isolated from the rest of the world, making travel complicated and expensive. This means islands have fewer overall resources, such as grocery stores, medical facilities, employers and educational choices. These resources often have a higher overall cost to residents. Food choices are likely to be relatively limited. Populations need to reach a certain level to make modern utilities, such as power plants and water treatment stations, cost effective, which means small islands may lack modern conveniences, such as running water, sewers or even a shared power grid. If the island is fortunate enough to have centralized utilities, an outage may take days to repair.
Like all small, isolated communities, island communities provide limited opportunity for dating but lots of opportunity for gossiping. With a limited population, it's hard to get away from other people if there's friction due to a failed love affair or a personality clash. Even if the island has a larger, growing community that negates many of these problems, land is likely to be at a premium with high rents.