My answer will be based mostly on "Strategy for Defeat The Luftwaffe 1933-1945", by Williamson Murray, which focuses on the luftwaffe but gives special insight to why the luftwaffe really lost.

at the morning of Operation Barbarossa the soviet air force was the biggest in the world and consisted of some 70 air divisions and 5 corpus. yet the soviet air force faced several problems. the first and foremost being that many of its officers were killed or incarcerated during purges in 1938, the other being that at 1941 the soviet air force was in a transitional period between generations of aircraft. many of its units still flew the biplanes Po-2, and I-152. the units that employed newer models were having trouble keeping themselves at operational levels, which what France faced a year earlier. but even then most of the newer fighters such as the LaGG-3 or the MIG-3 were inferior to the Bf-109. So couple the complete surprise, with the castrated command, low availability of fighters, and the rapid advance of the Germans caused staggering losses the soviets suffered in the first month.

the Luftwaffe faced severe problems too. the industry under Ernst Udet and Goering prioritized the delivery of whole aircraft to front line units and gave no thought for production of spare parts. so the front line units couldn't just fix damaged aircraft within a few hours, it often had to resort to cannibalizing damaged aircraft for parts. with this came the failure of the Wehrmacht logistical system to supply its troops in the east. so fuel and munitions were progressively scarce as the fighting went on. by autumn of 1941 the low serviceability of Luftwaffe squadrons was hampering its operations.

the soviets on the other hand started mass production of more and more improved aircraft, they were still largely inferior to German fighters, but the attrition the Germans faced with constant combat started taking its toll. by January 1942 flight cadets had their flight course shorten by a month, and in effect these new pilots had to be retrained and limited to less dangerous missions until they were ready, they also were much more likely to be involved in a fatal accident. this means that the experienced pilots now had to fly much more sorties, which increased the attrition in this demographic. this problem became more severe as front line units were withdrawn from the east to Africa or Germany to fight american strategic bombers.

by the time the Russians were bringing superior fighters to the front line, namely the La-5 and Yak-3/7/9 the war was already largely lost for the Luftwaffe. still untill the end of 1943 the germans could hold their own against soviet squadrons, yet in the battle of kursk the luftwaffe failed to gain air supiriority over the battle. as of 1944 they were less and less relevant.

It is a game of numbers, by the nature of total war everything is numbers, but it is not simply the number of soviet aircraft or pilots, it is a combination of elements that brought the defeat of the luftwaffe, much of it by the germans themselves.