So I sort of take issue with the basic premise of your question. That the carrier force was quickly scrapped and not supplemental to allies after the war, or made use of.

Of the Essex class and the 24 completed, just 2!, would never see active service following WW2. The Franklin and Bunker Hill had both been badly damaged, and while the damage could at least be repaired the USN actually kept these reconditioned ships in their pocket to use as basically blank slates for refits to try out, instead of needing to take an active ship out of service. However as larger carriers, heavier aircraft, and other Essex's soaked up more money and needs, the 2 were sold off for scrap in the mid 60's.

While the rest of the class got several decades of usage. The SCB-27 and SCB-125 programs were complex overhauls for the class which kept them useful for years. They added new catapults, rearranged the location of elevators, and added the now universal angled flight deck. That allowed carriers like Intrepid, Oriskany, and Bonhomme Richard to even deploy to Yankee Station off Vietnam along with their newer larger cousins like the Forrestals.

However the size of the ships, and power available for the catapults limited their viability intot he 60's. They were limited to operating lighter smaller jets, and turbo prop aircraft, or helicopters. While they could be useful for striking land targets in close proximity like Vietnam, for open ocean, or as part of a task force this increasingly limited what they could do. Many found themselves converted to helicopter carriers like Boxer, amphibious assault ships like Valley Forge, or as useful for ASW patrol aircraft carriers. Others found more unique usage, the Tarawa later became an aircraft transport. And also as a unique use the Antietam spent over a decade in Florida as a training carrier for Pensacola, followed by Lexington until the early 90's.

As to why we didn't sell off or transfer some carriers. Well we did actually. The French got 2 smaller carriers, and the Spanish 1. But consider that any other nation that had need had another buyer. The RN was selling off much faster and aggressively, and had a few easy customers. The Canadians and Aussies both took possession of ex-RN carriers, while the Argentinians, Brazilians, and even Dutch all bought some too.

While the British had their own stable of carriers and no need to buy any, and the French were not in a position to operate any large fleet carriers.

The USN was also unwilling to easily part with good usable hulls for carriers in the late 40's. As no new carriers were being built, and the Midway class had been cut in half the Carrier Admirals were anxious to not be the victim of the USAF seeking to establish primacy as the US military's air power wing. And if they could sell of a few of their carriers, why not all of them and let the Air Force do the job? The tension over the future of carriers and the Cancellation of the USS United States led to it spilling over into a series of sharp public comments and hearing known as the Revolt of the Admirals.