Metal ores are a finite resource. Once the rich ores have been mined and used, they cannot be replaced. Recycling metals means that scrap metal is collected, melted and made into new products, so the supply of valuable raw materials lasts longer.
Recycling also protects the environment. Mining destroys habitats and produces dust, noise and waste rock. Recycling means less mining and less rubbish sent to landfill. Recycling needs less energy than extracting a metal from its ore, so fewer fossil fuels are burned and less carbon dioxide is released. Recycling aluminium needs much less energy than extracting it by electrolysis.
There are economic advantages too. Using less energy saves money, and scrap metal can be sold, which also creates jobs in collecting and processing. The main drawback is the cost of collecting and sorting the scrap metal, because different metals have to be separated.