Answer briefly: Why are villi present in the intestine and not in the stomach?

The mucosal wall of the small intestine forms millions of tiny finger-like projections known as villi. These villi increase the surface area for more efficient food absorption.
Within these villi,there are numerous blood vessels that absorb the digested products of proteins and carbohydrates,carrying them to the blood stream. The villi also contain lymph vessels (lacteals) for absorbing the products of fat digestion. From the blood stream,the absorbed food is finally delivered to each and every cell of the body.
The mucosal walls of the stomach form irregular folds known as rugae. These help increase the surface area to volume ratio of the expanding stomach,allowing it to accommodate food.