Why is aluminum found in nature only in compounds?

Aluminum is a very active metal, therefore, pure aluminum is not found in nature. So in air, aluminum is oxidized to form aluminum oxide. If you peel off the top sediment from the aluminum wire, you can see pure metal, but over time, a film will appear on the surface of the metal again. It is due to the high activity of this metal that aluminum is found in nature only in the form of compounds. Aluminum is one of the most abundant elements on the planet, but the difficult process of extracting this metal from its compounds makes aluminum a very expensive metal.