The beam parallelism of flashlight is not high. After entering the eyepiece of the telescope, it is focused by the eyepiece and then shaped into parallel light by the objective lens, and a beam with very high parallelism (close to laser to some extent) can be obtained. Take the common 80mm diameter astronomical telescope as an example, so that a circular spot with a diameter of 80mm nearby and a distance of less than 0.5 m from tens of meters can be obtained.
Laser can also improve parallelism in this way. For example, it is often said that the distance to the moon is measured by laser, which is how the laser is emitted. Accept a bigger caliber reflecting telescope.