How much worse was it than the Nazi's?
For context, I'm trying to understand the extent to which these passages from Mearscheimer matters:
Stalin ruthlessly but effectively modernized the Soviet economy in the 1930s, so that by the start of World War II Germany enjoyed only a modest advantage in wealth over the Soviet Union (see Table 3.3). 48 Thus, the Soviet war economy was able to compete effectively with the German war economy in World War II. Indeed, the Soviets outproduced the Germans in virtually every category of military weaponry for the years from 1941 through 1945: 1) The Soviet Union produced 102,600 airplanes; Germany produced 76,200. 2) The Soviet Union produced 1,437,900 machine guns; Germany produced 1,048,500. 3) The Soviet Union produced 11,820,500 rifles; Germany produced 7,845,700. 4) The Soviet Union produced 92,600 tanks; Germany produced 41,500. 5) The Soviet Union produced 350,300 mortars; Germany 68,900. 49 No wonder the Red Army defeated the Wehrmacht on the eastern front. 50 [...]
Germany controlled some 36 percent of European wealth by 1940, while the Soviet Union possessed about 28 percent (see Table 3.3). In the spring of 1940, Germany conquered Belgium, Denmark, France, the Netherlands, and Norway and immediately began exploiting their economies, adding to its wealth advantage over the Soviet Union. 65 The Wehrmacht then invaded the Soviet Union in June 1941, and within six months Germany controlled almost all Soviet territory west of Moscow, which was prime real estate. By late 1941, the Soviet Union had lost territory that held 41 percent of its railway lines, 42 percent of its electricity-generating capacity, 71 percent of its iron ore, 63 percent of its coal, and 58 percent of its capacity to make crude steel. 66 In the spring of 1942, the Nazi war machine further extended its reach by driving deep into the oil-rich Caucasus region. The Soviet Union lost roughly 40 percent of its national income between 1940 and 1942. 67 Germany appears to have held more than a 3:1 advantage in economic might over the Soviet Union by 1942 (see Table 3.4). Despite Germany’s profound advantage in latent power, the Soviet war economy amazingly outproduced the German war economy over the course of the war and helped shift the balance of power in the Red Army’s favor. As described earlier, the Soviet Union produced 2.2 times as many tanks as Germany and 1.3 times as many airplanes between 1941 and 1945. What is most astonishing is that the Soviets even outproduced the Germans in the early years of the war, when German control of Soviet territory was at its peak and the Allied bombing campaign was having barely any effect on the German war economy. The Soviet Union, for example, produced 24,446 tanks in 1942; Germany produced 9,200. The ratio of artillery pieces for 1942 was 127,000 to 12,000 in the Soviets’ favor. 68 This asymmetry in weapons production eventually led to a significant Soviet advantage in the balance of ground forces. When Germany invaded the Soviet Union in June 1941, the Soviets had a slight advantage in number of divisions—211:199—the key indicator of military strength. By January 1945, however, there were 473 Soviet divisions and only 276 German divisions, and the average Red Army division was far better equipped with weapons and vehicles than the average Wehrmacht division. 69
It really depends on how you qualify "worse." Plenty of Soviet weapons were better than those of the Germans at various points in the war, and often times when there was a difference (particularly in small arms) the technological difference was less influential than the doctrinal differences. With aircraft, however, there was a clear technological gap.
Soviet aircraft radio technology as they entered WW2 was behind that of most other nations. Radio sets were very heavy and of limited use, often being unreliable and receive-only. At the outbreak of war, an alarmingly large number of pilots were removing the radios entirely to save weight, and even after reforms saw radios become more commonplace, the Soviets remained behind. One of the major selling points of Lend Lease aircraft (particularly the P-40 and P-39) for VVS pilots was their high-quality two-way radio sets, which were lighter, more capable, and easier to use than domestic sets. On the topic of Lend-Lease, there was also glaring shortages in high-altitude designs. The Soviets entered the war with an interceptor designed for high-altitude use (the MiG-3), but its performance was less than spectacular, and the Soviets had trouble dealing with German high-altitude reconnaissance aircraft (particularly the Ju-86P). Though there was work done on designing more modern high-altitude fighters to counter these high-altitude threats, the Soviets would rely on Lend-Lease aircraft to fill the high-altitude interception role, particularly the Spitfire Mk.IX and P-47.
As for the aircraft themselves, the Soviets went into the war clearly behind, but they generally caught up in most areas. The staples of the VVS when war broke out in 1941 were the I-16 monoplane fighter, I-153 biplane fighter, Tupolev SB "fast" bomber, and Ilyushin DB-3/Il-4. All of these were generally outclassed. The I-16 was a first-generation monoplane at the end of its design life and was completely outclassed by its German counterpart, the Bf 109, and the I-153 was the most modern biplane in a world that had abandoned the concept. The SB was roughly analogous to the Dornier Do.17 in that it was designed for the "fast bomber" doctrine of the interwar period, only to have fighter technology overtake it and leave it as a bomber with a comparatively light payload, poor armament, and inadequate speed. The DB-3 had significantly longer range and payload and was capable enough to become the staple of Soviet long-range aviation for much of the war, but it too suffered from woefully inadequate protection. The Soviets were caught in the early stages of modernizing their air force in June 1941, but many of the "modern" types coming in were underwhelming as well. Of the three modern fighters developed - the Yak-1, LaGG-3, and MiG-3 - only the Yak-1 had the performance to compete with the Bf 109 on relatively even terms. The Il-2 ground-attack aircraft, for all its fame, was incredibly vulnerable to fighters, and its poor payload left it fairly ineffective until the VVS had tailored its doctrine to suit it. Worse, it suffered from stability issues once the rear gunner was added, and only once the Il-2M had entered service in 1943 was this addressed. Of the "modern" types available in 1941, only the Pe-2 tactical bomber was free from glaring shortcomings.
A second generation of modern aircraft would come along in 1942 with better results, but the Soviet aircraft still lagged. The Yak-9 and La-5 both offered significantly better performance than the fighters they replaced, but they had their flaws. Early model Yak-9s had roughly similar performance to the Yak-1s, being equal to the Bf 109 in a turning fight but inferior in a vertical one. Later models with improved construction and engines would improve upon this and make the Yak-9 more on par with the Bf 109G and in some variants superior to the German piston-engined fighters by the end of the war. The La-5 had better performance on paper from the outset - on paper, it was comparable to the early Fw 190s - but like many designs, poor ergonomics and engine technology hampered it. The BMW 801 engine of the Fw 190 was a very advanced engine not just because of its power output, but its advanced control system that allowed the pilot to just push the throttle forward without having to manage much else with the engine. The La-5's ASh-82 engine lacked such capabilities, and thus required the pilot to hit a series of switches around the cockpit in the correct order before going to full throttle. German tests of captured La-5s would find that, while the La-5's performance was similar to the Fw 190, the poor ergonomics and complicated engine management made it far more difficult for pilots to make full use of the aircraft.
And there's a trend that would carry on through Soviet designs well into the Cold War. Ergonomics were a major issue among Soviet aircraft, and often the thing American Lend-Lease aircraft were highly praised for was their better ergonomic layout. The P-40 was highly favored because of its well-protected, high-sitting cockpit that afforded a much better field of view than any Soviet aircraft, for example.
The last consistent major technological shortcoming Soviet aviation had that I'm aware of was in engine technology. The aforementioned complicated controls of engines like the ASh-82 were a problem for many Soviet powerplants, and although it was also an issue the Axis powers as a whole suffered from, the Soviets struggled to develop a high-power piston engines or those suitable for high altitudes that were on par with what the Americans or British were churning out by the end of the war. More glaringly, the Soviets were very far behind with jet technology. While the Allies had developed their centrifugal-flow turbojets concurrently with the German axial-flow designs, the Soviets were completely unable to develop a functioning jet powerplant during the war. Much of their postwar development of jets relied on leveraging captured German research and engineers, and their first jet-powered fighters would leverage captured German powerplants. In the absence of captured German technology, the closest the Soviets would come to developing a jet powerplant was the Motorjet - an odd hybrid design where a piston engine (rather than a turbine drawing power from the jet exhaust) was used to drive the jet's compressor.