1. But it's not like these countries you mention are isolated islands.

This is an extremely simplistic way of thinking. I honestly will just ignore this response and focus on what matters.

The Marshall Plan played a huge role in speeding up reconstruction and development only in order to compete with the socialist bloc.

A. The Marshall Plan was implemented after WWII. So now you are contradicting yourself; did capitalism have centuries to develop, or did it improve rapidly through the Marshal Plan?

B. You are implying that the Soviet Union did not support its allies in the same proportion, which is false. This fact alone refutes your idea.

C. Spain and Finland weren't part of the Marshall Plan; and all countries besides France, Britain, West Germany and Italy received an insignificant amount of funds. For example, France received $2.7 billion, while Portugal received $51 million, Sweden $107 million. These are negligible numbers, and again, this fact alone refutes your idea.

The bloc was largely isolated from the same global market economy

The Soviet Union and its allies ruled over all of Central Asia, most of Eastern Asia, and all of Eastern Europe. All of these regions are resource rich and densely populated, so again, weak argument.

1. It takes long time initially for capitalism to develop out of feudalism but once it's done,

Stop here, it's not "done", it's a gradual but exponential process.

Now of course i don't assume you are going to attribute the great Bengal famine, late Victorian Holocaust or Irish potato famine to capitalism? Every lesser developed country in the world suffered greatly due to capitalism.

Obviously I won't because it's simply a false claim. The Bengali Famine happened because the British Empire used the national resources and used them for its military, effectively stealing them from the public. Under capitalism, private property should be protected, not stolen, so this has nothing to do with capitalism.

The Irish Famine was caused by British tariffs on most agricultural output except for potato, which made Ireland overreliant on potato and as a result, too susceptible to famines. Add to this the British persecution of Irish people and you have the perfect recipe for a famine. Again, completely due to state intervention. It's moronic to claim that this is caused by capitalism.

But regardless, you seem to be dodging the point. You claimed that the communist model is better because it industrializes faster, and I told you it's a tradeoff because this industrialization literally necessitates mass famines (we're talking about history's greatest).

Forced collectivization is necessary but not sufficient, I get it, but this doesn't prove my point, since it admits that the implementation of communism necessitates famines.

The famines you brought up were due to irrelevant factors, not economic system. Korea industrialized without any famine, and so did Japan, Poland, America, and literally most capitalist countries on Earth. On the other hand, you had 2 major communist countries and both of them lived through famines during the transition. Must be a coincidence, right? /s

East Germany suffered far worse during the ww2 with allied bombing and bitter fighting between nazi germany and ussr.

This is straight up false. So false that you can figure it out with 1 Google search. Here is a research. But it's not even a contested idea that West Germany got bombed to the bones, worse than East Germany.

North korea was practically bombed into stone age by USA.

Oh that's unfortunate. South Korea still outgrew China and Vietnam.

1. Sure, socialist countries had both better physical life quality and faster improvement in life quality baring famines which were disastrous.

Nope, they had much worse life quality as can literally be proven using the study you first mentioned. It's like you forgot everything I wrote and went back to the beginning. I will just end this discussion here because you are not even putting effort to learn what you don't know.