Why battleships remained useful after landings

Were battleships still useful after an amphibious landing was complete?

Yes; their heavy guns could continue supporting troops inland for as long as the battlefield remained within range.

Naval support did not end once troops crossed the beach. As long as targets remained within range, ground forces could call on battleship guns to break obstacles, suppress positions, and force defenders to relocate. Very heavy shells could persuade defenders to abandon an exposed position before an assault reached it. This sustained fire-support role explains why older capital ships retained operational value without fighting enemy battle fleets.