It was expensive and solved almost none of the actual problems
Difficulties distributing food within Gaza? Boats don’t work on land, so you end up loading it all into the exact same trucks you would use for land crossings, so run into the exact same issues.
Difficulties getting enough aid through Israeli checks? By design, Israel inspected all pier deliveries as they left Cyprus, and again as they arrived at Gaza, and the IDF controlled the staging beach within Gaza. If they were giving you problems at all the other crossings they control, they will give you the same problems at this one.
Distance between the crossing and where aid is needed? Sure. Technically this could help some depending on the details of the logistics work being done within Gaza. But… Gaza is just not that big.
Attacks by Hamas? As far as aid deliveries go, this has only ever been an issue internal to Gaza, so see point 1.
Attacks by starving Gazans? See point 1. Also, aid being stolen by starving people is mission accomplished
Egypt closing their border crossing? Sure, but again, Gaza is not that large, the Israeli land crossings are still fine.
Attacks by Israeli terrorists? Sure, but the Israeli police has been doing a fine job dealing with this already, so it has not been an actual bottleneck.
Attack by the IDF that hit people attempting to distribute aid within Gaza? See 1.
Lack of adequate practice for the US military to deploy a naval logistics platform? Fair enough, this project did solve that. Not sure what that has to do with the humanitarian situation in Gaza though.
At the end of the day, this pier project has always been the “something” to calls within the US that “we have to do something”.