WW2 is still the best air combat.
Yep.
WWI, you have the upper wing in the way of forward-up view, so not as popular for air combat.
Korean War, planes are too fast. So you get 1000 yard shots at a dot on the screen, and a long time to do a 180 degree turn. Combats are too slow, and range is too long.
Modern War, let some missiles fly at beyond visual range. How good are your computers, sensors, and missiles?
WWII is the golden age of dogfighting. The best combination of plane performance, view, range, time to do a 180.