It is possible that celebrities such as Kim Kardashian have introduced the modern contouring through their images on Instagram, but the contouring techniques are no longer exclusive to celebrities.
The practice of sculpting the face with makeup (as the contouring technique is defined), has become a technique applied by almost 100% of women.
Among the main benefits of the contouring are: 1- It highlights the best characteristics of your skin and 2-Makes your face look thinner. The contour has become a technique so used today, that women today are even trying to copy what they see in the images.
But as everything in life, you have to learn and practice so you can get to the stage of mastering contouring yourself.