Oh, why can't even carrier-based aircraft get rid of rockets?
It's about quantity, cost, and time. If an enemy launches a wave of cheap kamikaze drones at your aircraft carrier, they could overwhelm its defenses, because 1) each jet can only carry a handful of traditional air-to-air missiles, 2) those A2A missiles cost millions of dollars each, and 3) there might not be enough missiles per defending jet to shoot down all of the incoming targets. On the other hand up to 50 of these cheep rockets can be carried on a single plane, which increases the number of drones each defending aircraft can take down by nearly an order of magnitude, and they can do so at a fraction of the cost while saving valuable time. Sandboxx does a good analysis in this video: