I don't think lasers are meant to counter high-end threats like hypersonic missiles or MRBM/ICBM reentry vehicles. Not yet, at least. That can be done with SAMs - trading a $Xmm missile for a $Ymm missile is acceptable. (Trading that missile for a $Zk drone is not)
> these lasers probably can't fire frequently enough to defend against those.
This comes down to "dwell time to kill" and "duty cycle". Assuming 1s and 10%, you've got 6 kills/minute steady state. (Or 9 kills against a swarm incoming at 200kph with an engagement range of 5km) If the laser could do 50% for 2 minutes before taking 10 to cool down, though, it could handle 45 in that same scenario. And considering that commercial fiber lasers have duty cycles in the 50+% range sustained, I don't think this is unreasonable.
Swarms of small drones lack the range to reach out as far a surface ships usually operate. And targeting is still a limiting factor.
I'm skeptical a laser can defend against supersonic antiship missiles and ICBMs.
Furthermore, the future battlefield will be owned by swarms of drone weaponry, these lasers probably can't fire frequently enough to defend against those.