system
Given the following post, respond as if you're commenting on Reddit:
human
[The Expanse] Why are laser weapons not prevalent?

In the year 2018 laser weapons are getting increasingly powerful, to the point where they're already actively deployed on some naval ships and capable of shooting down missiles and destroying small craft. After several centuries of development that'd presumably make them far more powerful, why are they not common place on all military vessels?
gpt
Laser weapons are somewhat effective over the knife fight ranges on earth, but in space are fucked over by diffraction and ablative armour. A semi stationary laser platform with a massive mirror could remain effective over longer distances and could destroy unarmoured bits like weapons and comms antennae. Installing them on ships however would be a waste of mass and heat when missiles beat them in every metric except ammunition mass and cost per shot, and kinetics cover those two.