Marx had no experience at trying to run any government, and what he proposed was unworkable. Actually putting Marxism into practice was Lenin's job and he died before he could get the Soviet system working. Of course, the Russian Empire was huge, was mostly underdeveloped, and had been recently defeated in the war with Germany and Austria-Hungary and civil wars. Marx was German and Germans tend to do as they are told. Russians are far less obedient.
The Chinese have been most successful at running an entire country, by using capitalism as a tool for development. The Chinese have never been more prosperous than they are today.
No matter who runs China, the fact is that each citizen is only one of 1.4 billion people.
Income distribution in China is far more widely spread around than in the US. There are also more people incarcerated in the USA percentage wise than there are in China.
Would I prefer to live in China? No, I wouldn't, but am not Chinese.
Life is far more difficult, dangerous and short in many countries than it is in China. Annoying is ignorant and knows very little.