There are many methods that can be used to separate mixtures, depending on the physical properties of the substances involved. For example, if the substances have different boiling points, they can be separated by distillation. If they have different densities, they can be separated by centrifugation or filtration. If they have different magnetic properties, they can be separated by magnetic separation.
In contrast, compounds cannot be separated into their constituent elements by physical methods. This is because the elements in a compound are chemically bonded to each other, and the bonds can only be broken by chemical reactions.
Therefore, it is generally much easier to separate mixtures than compounds.