In alot less time that it took that fancy laser to down that drone, one 1/4 second burst from a vulcan would have obliterated it into cloud of tiny vaporous pieces.
If you are thinking about CIWS types, here’s the stats:
Rate of fire: 4500 rounds per minute, 75 rounds per second.
Number of rounds in the Phalanx mount: 1550
Round cost: $30 per round.
Minimum engagement: About 1.3 seconds - 100 rounds.
This means you only have about 15 or so potential engagements before the CIWS is useless for about 15 minutes while sailors attempt to reload the mount. Attackers will likely not be limited to sending just 15 drones.
Additionally, you spent $3000 per engagement against drones that may cost 1/10th of that to produce. Not exactly economically sustainable.
This is the laser system in the article: https://en.wikipedia.org/wiki/AN/SEQ-3_Laser_Weapon_System
It costs about $1 per shot and can keep firing as long as it has power. It has no immediate consumables and it doesn’t run out of ammo. It also has an effective range of at least 1600 meters versus Phalanx’s 1486.