In modern dogfights starting in WW II the easiest answer is cannon win dogfights. Early jet aircraft did not have much to go wrong, as they were essentialy WW II engineering solutions made of steel and aluminum with little to break if hit.
Ergo, a .50 caliber round striking one side and hitting nothing on its way through only leaves a .50 caliber hole on each side. Same with .303 -- which is why the Brits changed over to 20mm in the middle of WW II.
On the other hand, a 20mm round would blow a large chunk of airplane -- around a square foot -- off with one strike, plus damage or destroy what was behind it. A 23mm was similar and the 37mm round could devastate an aluminum structure with only one or two hits. Soviet estimates were 10-14 20mm or 23mm rounds to knock down a fighter, but only 1-2 37mm ones.
The F9F had four concentrated 20mm guns and could knock down a MiG with a short burst due to the explosive nature of the ammunition. Ditto the Yak-9T which carried an average armament of one 12.7mm machine gun and one 23mm cannon. The cannon was the killer.
Gabby Gabreski had a long section in one of his autobiographical comments about how the .50 caliber did not have the knockdown power to get a MiG, as even tracers would not start a fire at 40,000 feet against one.