Lasers imo don't really have IRL advantages over machine guns and rockets, and their line of sight nature is a huge limitation.
Laser:
- are cheap to shoot - do not fall on someones head if they miss (unlike firing bullets and rockets at a drone that will come down again) - do hit the target immediately if aimed right
Problems with lasers are, cooling, power consumption limiting mobile use - and indeed targeting and fog and clouds.
And rain.