The cerebral cortex is very wrinkled. how does the wrinkling make it more efficient?

From observation, we may have noticed our brains are very wrinkled. These wrinkles are called sulci while the ridges created from these wrinkles are called gyri. These sulci and gyri divide our brain into hemispheres and lobes. This wrinkling formation increases the amount of cerebral cortex that can fit in our skulls. Therefore, we have increased gray matter and more information can be fit and processed.