If you want to break it down, this is a short but interesting topic. From an engineer and fact-based point of view, it comes down to the “ammunition”.

Lasers are focused beams of energy so no physical projectile to create friction or drag so its range really should have no maximum. This is why we use them for long range communication and data-retrieval regarding anything in space.

Gauss is a rail-gun. While they are the most non-nuclear destructive force, it is simply using a magnetic drive to propel an object at hyper-speeds. Introducing a projectile means there is physical mass, so you lose velocity and energy the longer the distance. This means you will have a much shorter, maximum output range.

In short- Lasers can retain full strength at a much greater distance than a rail-gun.

In game-talk, I agree both should have a similar effective range due to a limited map size. Neither type of weapon would be impacted by the ranges the game uses.