They did.

The gunfire support component of the entire invasion included 5 battleships and some two dozen cruisers along with 2 BB's held as a reserve. Supporting Omaha itself were the BB's Arkansas and Texas along with 1 British and 2 French cruisers and force of destroyers. Numerous landing craft of all size also contributed, either having large batteries of rockets installed, or simply being platforms for artillery pieces as well.

The plan called for an about 1 hour bombardment followed by one last punch from the bombers before the troops came ashore at about 0630, however for only about half that time was it actually light enough to pick out targets on the beach as opposed to pre designated areas to work over.

Surprise was a major reason the beaches were not given the sort of extensive multi day working over you see elsewhere in the war. It is rather hard to not tip your hand when you are in hour 36 of pounding the defenses in one sector flat.

Operation NEPTUNE Plan and Components: https://www.history.navy.mil/research/library/online-reading-room/title-list-alphabetically/o/operation-neptune-invasion-normandy/chapter-4-neptune-operations-plans.html