I have made an island with many things like a Dock, Mine, floating island, Castle, a fountain and some other things. But I will be talking about the Mine and the Dock. The reason why I would want a dock is because If people came by they could land at the Island and help me out. If they were looking to mine for gold or coal because of his job. There would be a mine at the island for them to go down but they have to give me something and get me off the island.
You can also use Minecraft for writing like they have to build something and then take a photo and then write a story based on the scene they built. You can use it for maths for area and perimeter. Art as building a Minecraft build but you try it competitive for the best build. Also You can use it for fun and games.