Given that the aircraft supports itself by accelerating air downwards, how could those vortices not exist?
At a large scale, the air movement around a heavier-than-air aircraft takes the form of a torus, with air moving downwards in the middle and upwards at the periphery. In practice this torus is typically highly distorted because the aircraft is moving quickly and the air moves relatively slowly. A conventional wing tends to concentrate the rotation at the wingtips, resulting in a tight vortex with relatively high airspeeds and therefore sapping a significant amount of energy that isn’t directly contributing to generating lift. There are several ways to mitigate this, such as washout, tip plates, and closed oval wings; to differing extents these make the vortices less concentrated and so the air circulates less quickly and saps less energy.