Contrary to popular belief, coastal artillery systems can not be replaced by rocket systems, they complement each other. All coastal missile systems have "dead zones" from several kilometers to several tens of kilometers. This distance is just covered by artillery systems.
Another common question is why the A-222 “Coast” has a relatively small caliber. Disputes in the leadership of the Soviet Navy on this topic were conducted at the dawn of the creation of the complex. Three caliber variants were worked out: 203 mm, 152 mm and 130 mm. A plus of the first two calibers was complete unification with shells from the guns of the ground forces, as well as more serious firepower. However, the high rate of fire of 130-mm guns was a decisive argument.