Central planning in the USSR and China led to huge famines with millions of deaths.

And you should check what happened in Germany after the WWII: one country, split in two, one with central planning, other with mostly free market. Guess what was the result 40 years later? Same thing for Korea: one country, split in two, one with central planning, other with free market. The free market country gets western standard of living, central planning gets poverty, stagnation and famine.