Why does magnification not reveal more detail when viewing distant stars?

Magnification does not reveal more detail when viewing distant stars because they are so far away that they appear as point sources of light. Unlike extended objects such as the Moon or planets, which show surface features when magnified, stars remain points regardless of the magnification level used.1

Increasing magnification on a point source provides no additional advantage and can even degrade the quality of the image. High magnification amplifies any vibrations in the telescope's mounting and makes the image more susceptible to atmospheric seeing—the blurring caused by fluctuating air currents. Furthermore, the resolving power of a telescope, which determines its ability to distinguish between two closely spaced points, is limited by the diameter of the aperture and the physical phenomenon of diffraction, which creates a small pattern of light known as an Airy disk rather than an infinitely sharp point.123