Most common metals are rarely used in their "pure" state, except for very specific applications. Such is the case with "electrolytic" copper for electrical conductors. The same is true of aluminum. It is estimated that only 10% of worldwide consumption, mainly in electrical and packaging applications, is in the form of unalloyed aluminum.
The art of metallurgists is to create alloys from a base metal by adding to it, in measured quantities, one or more other metals (or elements) such as carbon in iron to make steel, tin in copper to produce bronze, and so on.
Alloys were developed to improve and modify certain properties of the base metal. Our distant predecessors in metallurgy, almost 5,000 years ago, discovered that adding tin to copper produced a metal, bronze, that was easy to cast. This is how statues, coins, weapons, fibulae and so many other objects were made, which we are delighted to discover in our museums (cf. Note).
Nota
According to some archaeologists, the cumulative production of bronze objects up to the 18th century was only around 10 million tonnes.