There were almost literal mountains of stuff over every variety stacked on little sand spits across the Pacific. Most of those crates were simply left to rot, simply because it was too costly to send a ship to collect it, load it, sail back to the States, unload it, and store it.
It is actually pretty cheap to build up those mountains and shift them around during the war when the personnel doing the moving are getting paid $1.75 a day regardless of number of hours worked (in 1945 a PFC made $54 a Month), but once the war is over and every voter expects their son/brother/husband/cousin to be discharged right GD NOW! and you now have to pay civilians around $1.52 an hour (with 1.5x for anything over 8 hours), which was the salary for West Coast longshoremen in early 1946, that same movement gets bloody expensive. Literally cheaper to let most of the stuff rot, or to give it to local governments/groups.