It is not war before WW1, who has the better technology and explosive weapon, who win. But somehow the commie still think they can win by soldiers spamming, e.g. Korean War.
Well you have to look at these "commies" and who they were...
Second Sino-Japanese War (CCP, KMT, Japanese). These forces did not a huge industrial base to churn out airplanes, tanks, and heavy artillery. Chinese forces especially lacked heavy artillery and mechanization.
Korean War: North Korea and China supply the soldiers and USSR supplies the tanks and planes.
Vietnam: I think everyone believes that the NVA just supplied an endless human wave to American bullet but they also fought conventionally with tanks and artillery. They were also very organized.
Really the whole point of this post is to show that these Commie countries lacked an industrial base to produce tanks, planes, etc, so they had to rely on infantry