Are Lubricants Viewed as Assets or Consumables?

Lubricants are far and large to be considered as consumables. With them alone, nothing much can be achieved. But when applied as a solution to reduce wear, take away heat, clean the engine, prevent rusting, provide smoother engagement of mechanical elements, a lot is achieved. Once that oil or that grease has been used, the usefulness is lost. The oil is degraded and another one is required.