First, hi F7Ftigercatlover, go back into the briefing room and look at your introductory thread. I posted 3 or 4 videos of Tigercats flying aerobatics at our airshows.
To the thread, from my long time interest the USAAF was WAY oversized after the war ended with tens of thousands of aircraft more than we had pilots in service. Naturally, a long war is EXPENSIVE. So, they looked around and decided that there were too many airplanes. Many types were "retired" from front-line service. Some were issued to Air National Guard units (reserve forces) around the various states. That way, the states would assume funding for maintenance, personnel, and operations unless the units were called up into active service.
In the Navy, they retired the Hellcat quickly for some reason, and retained the F4U Corsair. I believe the Cordairs were by and large newer, and were still being improved, and had a good supply of spares in the logistics pipeline. So we had Corsairs in active service and some in the Navy Reserves, and the Hellcats got largely scrapped with some winding up on the surplus market. Some went into private hands. TBMs, flying boats, and other bomber types wound up fighting forrest fires with the addition of tanks instead of torpedos or bombs. Some were converted into executive transports, like the Howard 250 and 350 (250 on top). See below. There were others like the On Mark Invader, too. Believe it or not, I've seen "Executive" versions of the B-25!
The USAAF knew jets were the future and quickly after the war had the P-80 that became the F-80 and rapidly also the F-84. The USAAF saw the F-84 as the fighter-bomber of the future and sent a lot of P-47s to National Guard units as well as selling many to other countries for their post-war air forces. Ditto the "extra" P-51 Mustangs. South America got a lot of ex-USAAF aircraft for their immediate post-war Air Forces, and could therefore take their time developing newer airplanes. Argentina used a lot of our WWII aircraft while they were trying to develop jets such as the Ta-183-like FMA IAe 33 Pulqui II with Kurt Tank. Plenty of other stories to go around.
The P-47 was a high-maintenance item that was OK as front-line equipment, but not so justifiable if being operated as a second-line aircraft. By second-line, I mean, obsolete or combat-weary. Once the maintenance hours per flight hour start to rise somewhat, the expense of operating a P-47 is enormous. It definitely needs a crew and parts to keep flying. If active on the front line (first-line aircraft), it makes sense. If not, then ...
Our museum (Planes of Fame) operates a P-47G and it is much less expensive to operate than a fully-functional Thunderbolt because the turbocharger has been removed and we have no armament or armor in it. It is many thousands of pounds lighter than in stock military trim. So the engine doesn't need the turbo system tweaked after every flight and isn't working nearly so hard as a fully functional P-47 engine would be. The airframe is fine but many systems were complex. If you remove the complex systems, it becomes MUCH cheaper to fly ... more like a normal R-2800 fighter. Of course if you DO that, it really isn't a combat-ready P-47 anymore, is it?
Likewise they sent a LOT of bombers into outdoor storage at many locations and retired many medium bombers, leaving just a few as "hacks" for the pilots to use logging time.
Anyway, my take on it is basically that we downsized and had to choose which equipment to continue using. I believe we chose the newer equipment with the most numerous recent spares to retain and rapidly divested ourselves of the rest. If we had 3 aircraft doing one job, we chose one and released the others. The Air Force upper brass and secretary's office probably made the choices, while the Navy brass and secretary of the Navy probably made their choices for the Navy and Marines.