You seem to be focusing on something quite beside the point. Anyway.
Under communism, China went from being "the sick man of Asia" to the most economically successful and politically powerful country in Asia, no?
It's the greatest single power on Earth other than the USA, no?
But perhaps under a capitalist regime China might have had even greater success?
Well, let us see:
How does one compare the stumbles of early Communist China to the consistent failure of capitalist India? Which path would you have preferred for your country?
China only started to succeed once Deng Xiaoping abandoned Marxist/Maoist theories of planned economy and embraced globalism in the 80's. The Chinese discovered they could game the globalist "free market" with low cost of labor, a weak currency, state-directed manipulation (dumping, etc.), and widespread IP theft. China's success in recent decades proves nothing about the virtue of Communism; the success would have not have happened without an pre-existing global capitalist order to parasitize. China's behavior has more in common with monopolist companies like Amazon than it does with Marx.
Didn't they start to succeed immediately with Mao (mass education, elimination of war-lords, expelling of foreign powers, etc.), and aren't the further successes you mention only possible due to Mao's achievements?
"Expelling of foreign powers" (i.e. Japan) happened due to WWII ending and China being allied with the winning side.
As for the others, these are modernization/consolidation of power which don't require Marxism to happen. Whether the KMT or someone else could have achieved these without a "Great Leap Forward" (30~45 million dead) is another question, but I think the answer is "probably".
> Under communism, China went from being "the sick man of Asia" to the most economically successful and politically powerful country in Asia, no?
I don't believe that's true, no. China does have a lot of natural resources, and a large population, and also it's true that any very authoritarian regime, fascist Italy under Mussolini being another good example, can do things like create good infrastructure, because it can have long-term bets. That is an accelerator for long-term economic growth. But the actual economic growth has come from China allowing capitalist economic systems to develop, where the people doing the work or risking the cash make decisions. Of course, Communism dies hard, and so if you say the wrong thing you can be "reminded" that the Party is all-powerful[0], but China has done well to allow individual people create value, evidenced by its economic growth.
OK, so, by Communist China you meant China after Mao took power but before capitalist economic systems developed.
Everything that has happened in China is possible only because of the victories of communism. From a non-existent school system (Mao managed to attend school because his father was the wealthiest in his village, but the schooling was nothing but rote memorisation of poems) to a well-educated population. From a nation controlled by war-lords to a nation controlled by the CCP. From a nation occupied by various foreign powers to a nation controlled by its own people, capable of controlling its borders. These were not the achievements of capitalism.
China had authoritarians before communism. Many countries has authoritarian leaders contemporaneous to Mao but achieved nothing. Mao's successes were not what "any" authoritarian could have achieved. It needed to be an authority with faith in the masses of its people, and an authority altruistic enough to put aside its own immediate interests for the good of the people. Fascism shares some of these qualities, but the fascists were expansionist, impatient, etc. Fascism lost, Mao won.
> Fascism shares some of these qualities, but the fascists were expansionist, impatient, etc
Well; fascism (or Nazism, maybe?) was socialistic ideas but on national boundaries rather than class boundaries. Hitler (mostly) wanted to kill non-Germans. Communist uprisings tend to kill their own citizens, and nonsensical edicts from hyper-powerful beaurocrats tend to starve same.
Under communism, China went from being "the sick man of Asia" to the most economically successful and politically powerful country in Asia, no?
It's the greatest single power on Earth other than the USA, no?
But perhaps under a capitalist regime China might have had even greater success?
Well, let us see:
How does one compare the stumbles of early Communist China to the consistent failure of capitalist India? Which path would you have preferred for your country?