The LASER and particle beams are electrically less efficient and more complex for tracking. However, both are pinpoint having small spot sizes.
Laser beams spread in the atmosphere, because the refraction index of the atmosphere depends on position. Electron beams can propagate in space.
The spread due to the position-dependent refraction index is one issue with a light beam, the next one is scattering of dust particles. As Stam wrote, electron beams can well propagate in space. However, you are, most probably, asking about large-scale focussing where electron beams indeed cannot be used. The beam will interact with the magnetic field - either the magnetic field of the earth or the interplanetary field due to the sun. The next issue is the interaction with other charged particle. For instance, in the interplanetary space, the solar-wind plasma will affect the motion of the free electrons from the beam. Such interaction is rather complex, it will depend on the concentration of the plasma particles, the energies, etc. Even without these effects, the electrostatic repulsion within the beam will cause defocussing on larger distances. All these effects make it very complicate to transport electrons or other charged particles over large distances. In contrary to that, space is almost transparent for the light, at least in our direct neighborhood. Therefore, light beams are preferable for tracking or scanning over large distances.
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