USA pilots got pulled back, if they survived, so they could teach the next batches of pilots. Experience had it's value. Most other nations, especially Axis, tended to use their pilots until they were KIA. Part of why as the war went on the Axis pilot quality was dropping.
Many of those Russian/soviet aces did that in an aircraft from the USA. One that many USA & UK pilots considered "inferior" and weren't thrilled to fly/use, was the Bell P-39 Aircobra;
en.wikipedia.org
Superseded by the Bell P-63 KingCobra;
en.wikipedia.org