The DDG-1000 Zumwalt class was a huge expensive mistake. Those ships only exist because after the old battleships were decommissioned, the Marine Corps convinced Congress that the Navy needed new ships to provide gunfire support during amphibious invasions. But the reality is that modern weapons have become so lethal that amphibious assaults against a heavily defended beach would be suicidal anyway even with naval gunfire.

The Zumwalt class is left as a ship without a mission. The guided artillery shells were cancelled due to cost overruns so there's no ammunition to fire out of the cannons. They have no area air defense capability and minimal antisubmarine capability. The smart move would have been to keep the first ship as a technology demonstrator and test article while cancelling the rest but instead they went ahead with building three of the stupid things.

Cost overruns and delays