What battleship guns could do that destroyer guns could not

What did battleship guns accomplish on D-Day that destroyer guns could not?

They destroyed the most heavily concreted German positions, targets that would have been extremely difficult for troops or lighter naval guns to eliminate.

Destroyer fire could support troops and engage many battlefield targets, but the hardest permanent positions demanded far more destructive weight. Battleship shells could smash fortifications that infantry or lighter guns would struggle to remove. The heavy guns earned their place against targets that lighter, faster fire could not destroy.