Why battleships still mattered in a carrier battle

Was the American battleship advantage worth anything in this carrier-centered battle?

Yes; battleships added air-defense weight and, more importantly, blocked enemy heavy ships from reaching vulnerable carriers where large-caliber gunfire would be catastrophic.

The American fast battleships formed a concentrated force that could support air defense and prevent Japanese heavy ships from reaching the carriers. Japan distributed battleships between escort and a heavy van intended for surface action. A 15-inch high-explosive hit could devastate an unarmored carrier or destroyer, so surface protection remained strategically meaningful even without a gun battle.