You don't need to sink a carrier to make it more of a liability than an asset.
If you hit its radar systems and/or damage the surface enough that landing becomes impossible, it becomes a sitting duck.
> That said, I wonder why you don't see Ukraine and Russia doing this more -- "saving up" for massive clouds of long range strike drones every couple weeks
To some degree, this happens. Journalists reporting from Ukraine already talk about some nights being silent, and then there are strikes with 600 drones or so. On the other side, Ukraine was really effective at using naval drone swarms to attack Russian naval ships.
Why not send even bigger swarm? I guess there are limits to how many drones you can effectively control at once. Data links saturate, and you risk losing a big swarm to jamming.
When Russia really wants to destroy a target in Ukraine, they use ballistic missiles, their interception rate is pretty low. Ukraine seems also pretty effective at destroying things in Russia, so air defense doesn't seem to be such a huge obstacle.
Finally, it feels like the Russia-Ukraine war is turning more and more into an economic battle. Ukraine is now at the point where money is more limited than weapons / ammunition, at least for some types of weaponry. Would saving up drones for a huge wave be a big economic advantage?
Otherwise, what stopped them from saving up all the bullets, artillery, or bombs and sending them out in brief pulses in prior wars...